Homeognathia flemingi (Heron & Damkaer 1978)

Lubbockia flemingi

MATERIAL STUDIED (Tables 1, 2).—NE PACIFIC: 6 females, 0.83–0.91 mm, NP 7 et al., (including: holotype, 0.83 mm, NP 7, USNM 168493; 2 paratypes, 0.84 mm, NP 13, 17, USNM 168495, 168496); 2 males, 0.84, 0.85 mm, NP 16, 26 (including: allotype, 0.84 mm, NP 16, USNM 168494). ANTARCTIC OCEAN: 1 male, 0.82 mm, AA 42.

FEMALE.—Average length about 0.85 mm. Prosome (Figure 18a,b) about 1.7 times length of urosome. Pediger 5 with slight transverse dorsoposterior sclerotized ridge. Genital segment with areas of external genital apparatus on anterior third of dorsolateral surface, each area with a setule. Genital segment and each postgenital segment with fine spinules on posteroventral margins. Uropod about 3 times as long as wide; outermost proximal seta about midsegment.

Rostrum with thickened posteroventral margin, deltoid in ventral view as shown in figure of orientation of oral appendages (Figure 18c).

Antenna 1 with armature and segmentation similar in number to that of L. minuta.

Antenna 2 (Figure 18c) with 1 seta on second segment. Third segment with inner setules and 3 subapical setae; armed terminally with 4 short claws and 3 setae.

Labrum (Figure 18d) with free margin divided into 2 rounded posteroventral lobes, each margin with row of hyaline setules and small dentiform processes on under surface; complex pattern of layers of tissue over- and underlying sclerotized areas.

Mandible (Figure 18e) with 2 outer elements, both with rows of setules; mandible blade with row of size-graduated scalelike denticles on median edge, and apical lash; concave edge of mandible base with a setulose element and rows of long setules.

Maxilla 1 (Figure 18f) flat, bilobed; 3 elements on each lobe.

Maxilla 2 (Figure 19a) first segment expanded. Second segment with a hyaline setule and stout setulose element; terminal bifurcate, setulose element; curved setulose element on inner margin.

Maxilliped (Figure 19b) 4-segmented. Second segment with a row and cluster of setules on inner surface (Figure 18c). Terminal segment a long claw.

Leg 1 (Figure 19c) with inner spine on basis, third exopod segment with 3 short outer spines. Leg 2 (Figure 19d) third exopod segment with 3 short outer spines. Leg 3 (Figure 19e) inner edge of third endopod segment with 3 setae. Leg 4 (Figure 19f) inner edge of third endopod segment with 2 setae. Legs 2–4 endopods with a small vented projection between terminal spines. Leg 1 coxa lacks an outer papilla, but a vent is present.

Leg 5 (Figure 18b) with free segment about 1/3 length of genital segment; 2 terminal spines with serrate, hyaline flange; outer spine slightly more than ½ length of inner, which reaches beyond posterior margin of genital segment.

Leg 6 probably represented by hyaline setule in area of external genital apparatus.

MALE.—Prosome (Figure 20a) about 1.7 times as long as urosome. Urosome (Figure 20b) with the 4 postgenital segments and uropods bearing spinules on ventral margin. Uropodal setae with relative lengths as in female.

Rostrum and mouthparts, except antenna 1, as in female.

Antenna 1 with segments corresponding to terminal 3 of female fused in male; armature similar to corresponding segments of female, except for addition of 1 esthete on segment 2 and 2 esthetes on segment 4; additional esthetes and 1 esthete on each of segments 6 and 7 somewhat longer than on female.

Swimming legs and leg 5 as in female with additions of clusters of short spinules on legs 1–4, most numerous on anterior surfaces of legs 1–3 and outer coxa and basis of leg 4.

ETYMOLOGY.—With the name Lubbockia flemingi, we wish to express our sincere appreciation to Professor Richard H. Fleming, Department of Oceanography, University of Washington, for our memorable introduction to oceanography.

DISTRIBUTION.—Northeast Pacific and Antarctic Oceans (Tables 1, 2); Southeast Pacific Ocean (Björnberg, 1973).