Cancellus typus H. Milne Edwards 1836

Cancellus typus H. Milne Edwards, 1836

Cancellus typus H. Milne Edwards, 1836:257–288, pl. 14: fig. 3; 1837:243–244.—Whitelegge, 1889a:232; 1889b:156.—Milne Edwards antl Bouvier, 1891:70; 1893:19. Sayce, 1902:152. Alcock, 1905:167 [list].—Hale, 1927:94–96, figs. 91, 92.—Gurney, 1939:99, 257. Hale, 1941:277–278 [juveniles], fig. 12.—Pope, 1944:247–259, 7 photos; 1947:129–132, 4 illus. Dakin, 1952:199, pl. 44.—Pope, 1953: 44–46, 3 photos.—Gordan, 1956:306 [list].

Gryllopagurus lithodomus Zietz, 1888:298–299, pl. 14: figs. 1–4. Cancellus lithodonrns.—Alcock, 1905:167 [list].—Gordan, 1956:305 [list].

MATERIAL.—1 ♂, 10.0 mm; Victoria, Australia; before May, 1908; Grant Collection; Australian Museum No. P334.—1 ♀, 9.1 mm; Coll. Endeavour Expedition; off Davenport and Launceston, Tasmania; before 1923; Australian Museum No. E6670.—1 ♀, 7.8 mm; Coll. Endeavour Expedition; Shoalhaven Bight, NSW, Australia; 15–45 fms; before 1909; Australian Museum No. E283; USNM 71003.

DESCRIPTION.—Cephalothoracic shield slightly wider than long; anterior margin of shield bordered by semicylindrical or flattened ridge in the shape of an obtuse W, with depressions interrupting ridge at postorbital indentations; rostrum armed at apex with spinule, not exceeding blunt lateral projections. Central and lateral depressed areas behind frontal rim connected by narrow channel behind postorbital notches; these areas smooth with scattered setae; central depression extending short distance posteriorly between two raised semicircular areas. Sculpturing on raised semicircles and on anterolateral part of shield consisting of rounded or flattened irregular ridges, generally transverse, or of large tubercles in uneven transverse rows. Heavy sculpturing only on anterior third of shield; central area smooth; many punctae on posterolateral areas of shield. Gastric pits elongate slits. Few setae around margins of shield; greatest number on anterolateral borders. Protuberance behind cervical groove with one or two tubercles armed with several setae.

Cardiac region longer than wide; calcification almost complete except for posterior areas; approximately 5 groups of setae along front border.

Anteromesial area of branchial region calcified with 2 or 3 well-defined groups of setae on forward part.

Ocular scales with inner half projected to a triangle armed with one or two terminal spines; occasionally an additional spine behind the terminal ones; many setae on projection.

Ocular peduncles much shorter than shield length; broader basally and distally; several groups of setae on a slightly raised line along the inner dorsal margin. Cornea not inflated. Base of cornea barely emarginated dorsally.

Antennular peduncle reaching about three-fourths length of eyestalk when extended; basal segment with 2 or 3 teeth; flagellum composed of about 20 segments.

Fifth article of antennal peduncle reaching approximately half or slightly more than half length of ocular peduncle. Antennal flagellum longer than ocular peduncle; flagellum with as many as 24 segments. Antennal acicle reaching one-third to one-half length of ocular peduncle, armed distally with 3 teeth, usually one additional tooth on inner margin behind these; many setae on all parts of acicle.

Opercular surface of cheliped flattened, slightly concave, extremely rough and tuberculate with many short strong setae. Dorsal margin of carpus in several raised lobes with setae on outer surfaces and projecting ridge. Inner margin of manus raised, divided into 5 to 7 separate tuberculate sections; tubercles on inner face of distalmost sections with corneous granule or denticle; dorsolateral margin rounded, channels between tubercles deeper there, but not extending down on outer face; several regular transverse striae on ventrolateral area of palm; on ventral margin, several raised areas with several blunt forward-projecting teeth and setae. Lateral surface of fixed finger and dactylus with strong toothlike tubercles on opposing margins; several tufts of long stiff setae on both fingers. Inner face of dactylus with two rows of 4 or 5 corneous granules; similar granules ornamenting inner surface of tubercles along dorsal margin.

Distal one-third of merus of P2 expanded on dorsal surface with longitudinal furrow. Dorsolateral edge of carpus slightly raised, sometimes in 4 or more distinct lobes, but fissures often very shallow and indistinct. Opercular surfaces of carpus and propodus concave; dactylus flat; all covered with numerous short setae. Outer margin of propodus raised in 5 distinct lobes, their edges seldom touching, short setae on dorsal and forward edges of lobes; 7 or 8 groups of tubercles on inner margin of propodus with tufts of setae from each group. Inner and outer margins of dactylus tuberculate, with many short setae; distinct line of corneous denticles on ventral margin, tufts of setae in rows on either side of line.

Merus of P3 broad, flat. Carpus with several forward-projecting lobes and setae distally, reduced proximally. Lateral margin of propodus with approximately 5 toothed projections, patches of strong setae on crests and smaller ones on inner and ventral surfaces in several longitudinal rows; denticle on distal ventral margin; some setae on external face. Dorsal margin of dactylus tuberculate with many laterally projecting setae; shorter setae in many clusters on inner face, few on outer face; row of tufts of setae ventrally on either side of line of 4 to 8 corneous denticles.

Round pad of corneous granules covering most of distal surface of propodus of P4, several tufts of setae on proximal uncovered portion. Dactylus not reaching end of propodus, with a row of granules and a few tufts of setae. Carpus with tooth on dorsal distal margin near the articulation with propodus; setae in groups along dorsal margin.

P5 with elongate pad of corneous granules on propodus, one row of granules extending onto fixed finger; dactylus with two irregular rows of granules and setae. Many long setae on all margins.

Female gonopores large, round, mesial on the proximal part of coxae of P3.

Front borders of basis, coxa, and ischium of P4 with heavy fringe of long, plumose setae.

Male gonopores (on inside anterior edge of the forward projection of the coxae of P5) much smaller than those of female; coxal projection expanded and thin anteromesially; broad depression in center of segment; many short setae on front margin on either side of and beneath gonopore.

Four hardened transverse strips across abdomen (remnant of first abdominal tergite close to junction with carapace). Tiny groups of setae arranged evenly over whole surface of abdomen. Females with four well-developed biramous pleopods on one side of abdomen; exopod usually shorter than endopod; anterior pleopods partly calcified.

Sixth abdominal tergite with a shallow median depression in front of transverse carina. Anterior lobe of plate depressed to lateral margins; anterior margin bordered by slight swelling on either side of midline; rounded tooth lateral to the swellings; lateral tooth on each side in front of carina; median longitudinal depression on posterior section; 2 to 4 rounded teeth on each posterolateral margin, several teeth mesially on posterior border. Small clusters of short setae evenly placed over entire surface of plate; several groups of longer setae on posterior margins.

Uropods covered with tiny clusters of setae; protopod smooth; posterior projection armed with only one lateral tooth and large round protuberance mesially. Setae along all margins of exopod and endopod much longer than those covering surface.

Telson with scalloped border creating a bilobed effect. Occasionally a few teeth on anterolateral borders; slight swelling medially with depressed areas anterolaterally. Longer setae on posterior margins.

COLOR.—“The color in spirit specimens is reddish, and especially the limbs are marked with large dark red spots, some of them encircling the legs, forming bands…. The pericardial cavity is marked by the branchio-cardial groove as a red shield. The branchial regions are of a pale horny color” (Zietz, 1888:298).

The preserved specimens available for examination had lost all traces of color.

TYPE.—Not in Museum National, Paris. Presumed lost.

TYPE-LOCALITY.—Unknown.

DISITRIBUTION.—Australia: off Port Jackson and Port Phillip, St. Vincent Gulf; and off Devonport, Tasmania; sublittoral.