T. XIIl] CRUSTACEA CASPIA, 417 



ing the dorsal part of the last 2 segments of mesosome quite uncovered, la- 

 teral lobes not even obtecting the sides of the last segment (see fig. 1 8), 

 cephalic part about as broad as the 1st segment of metasome, and having 

 the infero-lateral corners produced to acute anteriorly curving projections, 

 rather conspicuous also in the dorsal view of the animal (see fig. 1 & 2), 

 anterior edge considerably produced in the middle, though evenly rounded 

 at the tip. Eyes (see fig. 2) rather narrow, nearly cylindrical in form, and 

 considerably projecting laterally beyond the sides of the carapace, corneal 

 part but slightly expanded, and occupying dorsally only l / z of the length of 

 the eye, its inner edge nearly straight. Superior antennae with the peduncle 

 (fig. 3) but little longer than the eyes, last joint having in female only a 

 single plumose seta at the inner corner, the latter being in male (see fig. 1 9) 

 produced to a narrow digitiform process, male appendage (fig. 20) scarcely 

 more than half the length of the peduncle and very narrow. Inferior antennae 

 (figs. 4 & 21) with the outer corner of the basal part produced to a very 

 strong anteriorly curving spiniform projection, scale in female (fig. 4) about 

 twice the length of the peduncle of the superior antennas, and regularly lan- 

 ceolate in form, about 4 times as long as it is broad, with the inner edge 

 somewhat arched in its proximal part, apical segment occupying about */ 4 of 

 the length of the scale and bearing 1 2 of the marginal setae, 3 issuing from 

 the tip; apical segment in male (see fig. 21) freely movable upon the remain- 

 ing part of the scale, by the aid of a strong muscle quite wanting in female, 

 its tip (fig. 21) produced to a spiniform or nearly hook-shaped point curved 

 downwards. Guathopoda (fig. 11) with the basal part very large and fringed 

 interiorly with strong plumose setae, apical spines (see fig. 12) about 13 in 

 number, all of same appearance, though the median one (the dactylus) ap- 

 pears a little stronger than the others. Pereiopoda (fig. 1 3) with the ischial 

 and meral joints nearly equal- sized, and having on the inner edge numerous 

 fascicles of slender setae, tarsal part about same length, with the 1st joint 

 somewhat longer than the other 2 combined, 3rd joint (see fig. 14) forming 

 at the end interiorly a slight nodular projection armed with 2 short spines, 

 dactylar joint (ibid.) very small and having at the base of the terminal claw 

 2 somewhat unequal spines. Outer sexual appendages of male (fig. 22) di- 

 stinctly bilobular at the tip, the anterior lobe more projecting and fringed 

 with long stiff bristles. Fourth pair of pleopoda in male (fig. 24) reaching 

 scarcely to the end of the last segment of metasome, basal part produced 

 at the outer corner to a triangular projection, outer ramus somewhat irre- 

 gularly twisted, having the inner edge biangular on the middle and armed, 

 at the base of the flagellar part, with a small hooked projection. Telson 

 (fig. 16) much shorter than the last segment of metasome, and rather broad 



Dnllctin N. S. IV (XXXVI) p. 69. 



