Philomedes lilljeborgii (Sars 1866) Sars 1869

Philomedes lilljeborgii (Sars, 1865)

Bradycinelus Lilljeborgii Sars, 1866[1865]:112.

Philomedes bonneti Kornicker and Caraion, 1977:6, figs. 6–10, pls. l–4.—Kornicker, 1982:23 [key].

Philomedes species B.—Kornicker. 1985:410–412.

Philomedes lilljeborgii—Kornicker, 1987:877, figs 1, 2a–d [see for complete synonymy].

HOLOTYPE.—Lost (Skogsberg, 1920:409).

TYPE LOCALITY.—Near Drobak, Christiania Fjord, Norway, 110–183 m.

MATERIAL.—BIOGAS I, R.V. La Perle, sta Hors-Zone: sample DS-04, USNM 193250, 8 specimens. BIOGAS II, R. V. Jean Charcot, sta Hors-Zone: sample DS-34, 4 specimens and 1 adult female (USNM 157979) + 19 specimens. BIOGAS III, R.V. Jean Charcot, sta 1: sample DS-36, 1 ovigerous female (USNM 193249) + 1 adult male (USNM 193247) + 2 adult females (USNM 193248) + 78 specimens.

DISTRIBUTION.—West of Bay of Biscay, 1031–2147; off Mauritania, 1120 m; west coasts of Norway and Sweden, 50–914 m.

SUPPLEMENTARY DESCRIPTION OF ADULT FEMALE (Figures 35, 36).—Carapace with prominent rostrum, broad incisur and small but distinct caudal process (Figure 35a); inferior corner of rostrum with minute protuberance.

Ornamentation: Carapace smooth with bristles along anterior, ventral, and posterior margins, and sparsely distributed on lateral surface.

Infold: Broad along anterior, anteroventral, and posteroventral margins and narrower ventrally and posteriorly; infold on rostrum with 25–30 bristles (bristles spinous and divided except for 3 or 4 bare and shorter bristles along ventral edge of incisur); 1 minute bristle on infold posterior to incisur, anteroventral infold with about 14 striae and 20 or 21 short spinous bristles along list; no bristles along middle part of ventral list; posteroventral and posterior infold with numerous small bristles along raised list (about 57 bristles in groups of 1–4 bristles); infold of caudal process with narrow flap forming pocket (pocket open ventrally) parallel to ventral margin of valve (Figure 35b); ventral margin of flap with 6 or 7 short bare bristles; 1 short bare bristle present on infold about midway between anterior end of flap and ventral margin of valve; 1 or no short bare bristle present between flap and list.

Selvage: Lamellar prolongation with marginal fringe present along anterior, ventral, and posterior margins of valve; prolongation segmented along rostrum and incisur, and divided at inner end of incisur; long filaments with bases on lateral side near longitudinal suture present on selvage below incisur.

Size: USNM 157979, length 2.10 mm, height 1.46 mm; USNM 193249, length 2.17 mm, height 1.46 mm; USNM 193248A, length 2.11 mm, height 1.43 mm; USNM 193248B length 2.12 mm, height 1.42 mm; USNM 193246, length 2.07 mm, height 1.41 mm.

First Antenna (Figure 35c): 2nd joint with lateral spines forming row in distal anterior corner.

Second Antenna: Protopodite bare. Endopodite (Figure 35d): 1st joint with 6 bare bristles (5 proximal, 1 distal); 2nd joint with 3 or 4 ventral bristles and 1 recurved dorsal bristle near tip (Table 8). Exopodite: 1st joint with minute, straight, medial bristle on distal margin; bristle of 2nd joint with few, small, proximal, ventral spines; bristles of joints 3–5 bare; bristles of joints 2–5 about half length of bristles of joints 6–8 as well as long bristles of 9th joint; bristles of joints 6–8 long, with natatory hairs; 9th joint with 7 bristles (4 long with natatory hairs; 2 short with natatory hairs, 1 very short with small marginal spines); long bristles broken on specimen with larvae; joints 2–8 with spines forming rows along distal margins; some joints with basal spines but obscure on specimen examined.

Mandible (Figure 35e, f): Coxale with spinous and bifurcate endite with small ringed bristle near base. In addition to 2 subterminal bristles, dorsal margin of basale with 3 or 4 distal bristles (Table 8). Proximal group on dorsal margin of 1st endopodial joint with 5 bristles. Medial surfaces of basale and 1st and 2nd endopodial joints with spines forming rows.

Maxilla: Coxale with stout hirsute dorsal bristle. Distal margin of basal with 4 bristles (2 closely spaced dorsal, 1 ventral, 1 medial). 1st endopodial joint with 1 alpha-bristle (with long proximal and short distal spines) and 4 or 5 beta-bristles (most with short marginal spines). Exopodite with short, bare bristle close to 2 terminal bristles bearing long marginal spines.

Fifth Limb (Figure 36a-c, h, i): 1st exopodial joint anterior side with 2 bristles near midwidth (inner brisde with small spines along inner edge; outer bristle with few long spines near middle and minute spines along inner edge (Figure 36a), and 1 short spinous bristle with stout base near outer corner of joint; anterior surface of joint hirsute and with spines forming clusters near broad base of short outer bristles. Main tooth with 4 constituent teeth (distal toodi with 4 small teeth proximal to larger terminal tooth and with large bifurcate anterior tooth; tooth proximal to distal tooth with total of 11 small marginal teeth; next tooth smaller and with about 12 small marginal teeth; 4th tooth slender and with faint spine-like marginal teeth); spinous bristle proximal to 4th tooth (Figure 36h,i). 2nd exopodial joint: outer edge of large triangular tooth forming joint with small hirsute bristle; posterior side with stout c-bristle with distal marginal spines and 3 bristles forming row (middle of these stout and with distal spines; others short and either bare or widi faint spines); inner curvature of triangular tooth with 2 teeth (proximal of these with 2 minute teeth, other with 3; Figure 36b, i). 3rd exopodial joint: inner lobe widi 3 bristles (proximal bristle slender, middle bristle stout, pectinate, and with long proximal spines; distal bristle longer than middle bristle (but not as stout), pectinate and with long proximal spines); outer lobe small with 2 hirsute bristles. 4th and 5th joints fused, with total of 6 spinous bristles. Epipodial appendage with about 50 bristles.

Sixth Limb (2 specimens examined)(Figure 36d): Endite I with 2 short medial bristles with long proximal hairs and short distal spines and 1 long terminal bristle with wreaths of long spines; endite II with 1 short medial bristle with long proximal hairs and short distal spines and 3 long terminal bristles (2 with wreaths of long spines, 1 with long proximal and short distal spines); endite III with 1 proximal bristle with long proximal hairs and short distal spines and 8 spinous terminal bristles; endite IV with 1 medial bristle with long proximal hairs and 9 terminal spinous bristles. End joint with 23–27 spinous and hirsute bristles (Table 8); 4 short bristles with long proximal hairs and short distal spines in place of epipodite.

Seventh Limb (Figure 36e): Each limb with 9–11 bristles (5 or 6 terminal, 2 or 3 on each side, and 5 or 6 proximal, 2 or 3 on each side) (Table 8); each bristle with 4 or 5 bells (usually 5); hairs present on bristles proximal to bells. Terminus with comb of 14 teeth (each tooth with alar projection on each side and a rounded tip; middle toodi about same length as adjacent lateral teeth); side opposite comb with 10–12 elongate pegs forming 2 rows (5 to 7 pegs in each row).

Furca (Figure 36f): Each lamella with 10 claws decreasing in lengtii along lamella; claw 1 of right lamella slighdy anterior to that of left.

Bellonci Organ (Figure 36g): Elongate with or without faint suture at small restriction near middle; tip rounded.

Eyes (Figure 36g): Lateral eye minute, indistinct, with few small globules. Medial eye well developed with light amber pigment.

Upper lip (Figure 36f): Typical for genus.

Anterior of Body (Figure 36g): Process with rounded tip present between upper lip and medial eye.

Posterior of Body (Figure 36f): Posterior of body just dorsal to furca with hairs; posterodorsal corner of body bare.

Y-Sclerite (Figure 36f): Ventral branch closer to distal end of sclerite tiian to proximal end, forming right angle with dorsal branch.

Eggs: USNM 193249 with 19 and USNM 193248A with 17 well-developed eggs in marsupium.

SUPPLEMENTARY DESCRIPTION OF ADULT MALE (Figures 37, 38).—Carapace more elongate than that of female, with more open incisur and with rostrum tapering anteriorly (Figure 37a).

Ornamentation: Carapace smooth with long undivided bristles; most bristles with broad basal part and sparsely distributed over valve surface, and especially numerous along anterior and anteroventral margins and near posterior margin.

Infold: Infold of caudal process similar to that of female (Figure 38b). Infold elsewhere not examined in detail but, in general, similar to that of female.

Size: USNM 193247, length 2.21 mm, height 1.18 mm.

First Antenna (Figure 37c): 1st joint bare. 2nd joint spinous with 3 bristles (1 ventral, 1 dorsal, 1 lateral; ventral bristle almost reaching distal end of 5th joint, with wreaths of long spines near midlength; lateral bristle slender, about length of ventral bristle, with short marginal spines; dorsal bristle slender, about length of ventral bristle, with short marginal spines). 3rd joint short, with 1 long ventral bristle (with long spines near midlength and short spines distally) and 3 dorsal bristles (2 long with long spines near midlength; 1 very short with short marginal spines). 4th joint about twice length of 3rd, with 4 ventral bristles and without dorsal bristle (probably broken off). 5th joint small, wedged ventrally between 4th and 6th joint; sensory bristle with stout proximal part bearing abundant filaments and distal part with 5 shorter terminal filaments (1 terminal filament with base proximal to others). 6th joint slightly shorter than 4th joint, with slender medial bristle (about same length as joint) with long spines near midlength. 7th joint: a-bristle about same length as bristle of 6th joint, with short marinal spines; b-bristle stout, about twice length of a-bristle, with 3 proximal and 5 terminal filaments (including stem); c-bristle very long and with about 12 short filaments. 8th joint: bare d-bristle about 2 times length of a-bristle; e-bristle unusually long, about 3 times length of a-bristle; f-bristle very long (about twice length of stem), with about 13 short marginal filaments; g-bristle about same length as b-bristle, with 3 proximal and 4 terminal filaments (including stem).

Second Antenna: Protopodite bare. Endopodite 3-jointed (Figure 37d): 1st joint short, with 5 proximal and 1 distal bristle, all about same length; 2nd joint elongate, with 3 ventral bristles with short marginal spines (2 distal bristles separated from each other by space equal in length to diameter of base of bristle); 3rd joint reflexed, with proximal bristle about length of joint and 2 small subterminal bristles; tip of joint with about 6 ridges; inner margin of joint undulate and sclerotized. Exopodite: 1st joint with few lateral spines forming distal rows and small straight medial bristle on distal margin; 2nd joint about length of 1st, with bare bristle reaching to about 6th joint; 3rd joint about longer than 2nd; bristles of joints 3–8 with natatory hairs, no spines; 9th joint with 6 bristles (4 long, 2 short), all with natatory hairs; joints 2–8 with spines forming rows along distal margins; joints 3–8 with small basal spine increasing slightly in length on distal joints; basal spine of 8th joint about length of joint.

Mandible (Figure 38a): Coxale endite comprising small bifurcate process with small bristle near base; both branches pointed but dorsal branch shorter and with few marginal spines. Basale: dorsal margin with 3 or 4 (usually 4) slender spinous bristles in addition to terminal pair (Table 8); medial side spinous, with 5 bristles at proximal ventral corner (2 ringed, 3 unringed, all with short marginal spines) and 1 longer ringed bristle (with long proximal and short distal spines) closer to midlength of joint; lateral side near ventral margin with 4 bristles with long proximal and short distal hairs (proximal of 4 with base on ventral margin); ventral margin with 2 stout terminal bristles with wreaths of long spines. Exopodite reaching just past midlength of dorsal margin of 1st endopodial joint, hirsute distally and with pointed terminal process; proximal bristle just slightly longer than distal bristle (longest bristle on right limb of specimen examined bearing long spines at midlength). 1st endopodial joint with medial spines forming rows on ventral half, and with 5 stout, spinous, ventral bristles. 2nd endopodial joint with abundant medial spines forming rows; ventral margin with spines and 6 distal bristles (with short spines) forming 2 groups with 3 bristles in each group; dorsal margin with bristles forming 3 groups at joint midlength (proximal group with 2 bristles, middle group with 1 bristle, distal group with 5 or 6 bristles. End joint with 3 claws (all with ventral spines; dorsal claw about half length of longest claw) and 4 or 5 ringed bristles (3 or 4 ventral, 1 dorsal).

Maxilla: Reduced, with 3 endites bearing slender hirsute bristles. Precoxale and coxale with fringe of dorsal hairs; coxale with stout hirsute dorsal bristles. Basale with 4 distal bristles: 2 dorsal, 1 medial, 1 ventral, all with long marginal hairs. Exopodite with 2 long terminal bristles and 1 short subterminal bristle, all with long marginal hairs. 1st endopodial joint with long hairs forming rows (absent along dorsal margin), 1 slender alpha-bristle with long marginal hairs, and 4 slender beta-bristles with long marginal hairs. End joint with about 11 weakly developed bristles.

Fifth Limb (Figure 37f): Limb reduced; epipodite with about 46 bristles; 3 endites with slender weakly developed bristles. 1st and 2nd exopodial joints obscure but each with 1 or 2 broad flat unringed bristles with marginal hairs. Inner lobe of 3rd joint with 3 slender ringed bristles; outer lobe hirsute with 2 stout, long, hirsute bristles, Fused 4th and 5th joints hirsute with 6 slender ringed bristles, some with marginal hairs.

Sixth Limb (Figure 38b): 1–3 ringed bristles (with hairs on proximal half) in place of epipodite. Endite I with 2 medial bristles (with long proximal hairs) and single terminal bristle; endite II with single medial bristle and 3 terminal bristles, all with long proximal hairs; endite III with single medial bristle (with long proximal hairs) and 7 or 8 terminal bristles (most with long hairs except near tip); endite IV with a single medial bristle (with long proximal hairs) and 8 or 9 terminal bristles (most with long proximal hairs). End joint with 17 or 18 bristles (posterior 2 hirsute and most others also hirsute except near tip (Table 8). Limb hirsute.

Seventh Limb (Figure 38c): Each limb with 11 or 12 bristles (5 or 6) terminal, 2 or 3 on each side, and 5 or 6 proximal, 3 on each side (Table 8); bristles with few hairs proximal to bells. Terminus with comb of 10–12 teeth; each tooth with alar projections on each side and rounded tip; middle tooth only slightly longer than adjacent teeth; side opposite comb with 7 or 8 elongate pegs forming 2 rows with 3–5 pegs in each row.

Furca: Each lamella with 9 claws decreasing in length along lamella; claw 1 of right lamella slightly anterior to that of left; claws 1–6 with long spines forming medial row near base; claws 7–9 without medial spines; anterior distal corner of each lamella near base of claw 1 with few spines; additional spines forming short medial rows just within anterior edge of right lamella.

Bellonci Organ (Figure 38e): Elongate with suture at narrow part near midlength; tip rounded.

Eyes (Figure 38f): Lateral eye amber, well developed, with about 27 ommatidia (12–16 of these larger than others and forming rows, each with 4 or 5 divided ommatidia). Medial eye amber, about same size as lateral eye, bare.

Upper Lip, Anterior and Posterior of Body, Y-Sclerite: Similar to those of female.

Genitalia: With elongate copulatory organ on each side of body, each with 2 or 3 lobes bearing few small bristles.

VARIABILITY (Table 8).—Variability in numbers of bristles on the ventral margin of the 2nd endopodial joint of the 2nd antenna, the dorsal margin of the mandibular basale, the end joint of the 6th limb, and the 7th limb are given in Table 8.