588 



4. Ischyrocerus anguipes, Kroyer. 



(PI. 209). 



Iscliyrocerus anguipes, Kroyer, Gronl. Araphip., Danske Vid.-Selsk. Afh. VII, p. 283, PI. Ill 



fig. 14. 



Syn: Gammarus zebra, Rathke. 

 Podocerus anguipes, aut. 



Body rather slender, especially in the male, with the back evenly 

 rounded throughout. Cephalon about the length of the first 2 segments of 

 mesosome combined, lateral lobes obtusely angular, with the inferior edge 

 gently curved. Coxal plates in female successively increasing in size to the 

 4th pair, which are considerably deeper than the corresponding segment, 5th 

 pair with the anterior lobe nearly as deep as the preceding pair; those in 

 male comparatively less deep and also less unequal in size, the 2nd pair 

 being fully as broad and nearly as deep as the 4th. Last pair of epimeral 

 plates of metasome obtusangular. Eyes comparatively small, rounded, placed 

 near the lateral lobes of the cephalon, pigment dark brown. Superior antennae 

 somewhat exceeding in length 1 /s of the body, 2nd joint of the peduncle the 

 longest, 3rd joint much longer than the 1st, flagellum scarcely exceeding hall 

 the length of the peduncle, and composed of 6 articulations, accessory 

 appendage nearly as long as the 1st articulation of the flagellum, and 

 Inarticulate, the terminal joint very small, Inferior antennae in female but 

 little longer than the superior, last joint of the peduncle somewhat longer 

 than the penultimate one, flagellum about the length of the latter joint and 

 5-articulate ; those in male much more elongated than in female, and rather 

 strongly built, with the last 2 joints of the peduncle about equal-sized, 

 each being much longer than the flagellum. Anterior gnathopoda in both 

 sexes rather feeble, propodos somewhat expanded, with the lower edge evenly 

 curved, and armed with 2 small spines near the middle. Posterior gnathopoda 

 in female of about same shape as the anterior, though somewhat larger ; 

 those in male very large and, when fully extended, about half the length of the 

 body, meral joint produced in front to a narrow mammilliform projection, 

 propodos very much elongated, and nearly of equal breadth everywhere, 

 being distinctly curved, with the upper edge boldly convex, the lower, concave 

 and densely setous, palm not defined, but produced in front to a narrowly 

 1 rnucated prominence, finely denticulated at the tip, dactylus falciform, with 

 the inner edge slightly bulging in the middle. Pereiopoda rather strongly 

 built and edged with fascicles of stiff bristles, basal joint of the 3 posterior 



