490 6. 0. SARS, [t. XIII 



western part of the North Caspian Sea, off the Tschistyi-Bank. Solitary spe- 

 cimens were moreover captured at Stat. 48, almost in the same tract, and at 

 Stat. 53, north of the islands of Kulaly and Morskoj. 



8. Pseudocuma bilamellata, G. 0. Sars, n. sp. 

 (PI. X and XI). 



Specific Characteristics. — Body comparatively slender and elongated, 

 especially in the male, with the anterior division considerably shorter than 

 the posterior and oblong oval in form. Carapace of moderate size, with the 

 branchial regions sharply defined from each other by a low crest running 

 along their most prominent part, and suddenly bent downwards in front; 

 gastric area provided with 2 parallel, longitudinal keels, and terminating with 

 a rather broad and transversely-truncated ocular lobe ; pseudo -rostral projec- 

 tion of a rather unusual shape, being divided by a deep incision into 2 juxta- 

 posed, thin, oval lamellae pointing somewhat obliquely upwards; antero-lateral 

 corners in female nearly rectangular, in male more obtuse. Free segments of 

 mesosome without any keel or projections above, but rather sharply defined, 

 and having the epimera very broad ; the 3 anterior ones rather short in their 

 dorsal part, the 2 posterior comparatively large and massive. Metasome con- 

 siderably more elongated in male than in female. Eye in male well developed, 

 in female with only 2 corneae placed wide apart. Superior antennae rather 

 elongated, with the last joint of the peduncle the longest. Inferior antennae 

 in male not attaining the length of the body. First pair of legs comparatively 

 slender, and in male having the basal joint much curved; 2nd pair rather 

 different in the two sexes, being much larger in the male, and having the 

 terminal joint armed with recurved hooks. The 3 posterior pairs of legs 

 rather strongly built, and of a structure similar to that in P. tenuicauda. 

 Uropoda comparatively strong, with the scape densely setiferous inside, and 

 the rami equal-sized, the inner one coarsely spinulose inside, apical spines 

 in both comparatively short. Telson nearly quadrate in form. Length of adult 

 female 9 mm, that of male 10 mm. 



'Remarks. — This is a very distinct species, easily recognizable from any 

 of those previously described, and especially clearly distinguished by the 

 peculiar shape of the pseudo-rostral projection, which is, at is were, double, 

 being divided by a deep incision into 2 juxtaposed, thin lamellae: hence the 

 specific name. 



Description of the female. 



(PI. X). 



The length of adult ovigerous specimens measures about 9 mm., and this 

 form thus belongs to the larger species of the genus. 



Bulletin N. S. IV (XXXVI) p. 826. 



