CRUSTACEA CASPIA.* 451 



densely fringed all rouud with set*. The inner ramus is very small and 

 scale-like. •' 



The telson (fig. 10) has the lateral lobes obtusely pointed, and each 

 armed on the tip (see fig. 10 a) with 2 short sjjines accompanied by some 

 delicate hairs. 



Occurrence. — This form has been collected in great numbers by 

 Dr. Grimm, in the mitldle and southern parts of the Caspian Sea, the depth 

 varying fi-om 35 to 108 fathoms. 



13. Gammarus subnudus, G. 0. Sars, n. sp. 



(PI. G, figs. 11 — 19). 



Specific Characters. — Body somewhat tumid and quite smooth tlu'ough- 

 out. Cephalon with the lateral lobes rather broad and somewhat obliquely 

 truncated at the tip, the inferior corner being the more prominent. Anterior 

 pairs of coxal plates comparatively large and broad, especially the 4th pair. 

 The last 2 epimeral plates of metasome nearly rectangular. Urosome with- 

 out any spines or projections dorsally. Eyes oblong oval. Superior antennae 

 comijaratively short, though a little longer than the inferior, flagellum about 

 the length of the peduncle, accessory appendage rather small, 3-articulate. 

 Gnathopoda in female rather unequal, the posterior ones being much the 

 stronger. Pereiopoda not very elongated, and almost naked, basal joint of 

 antepenultimate pair sub(iuadrangular, that of last pair considerably ex- 

 panded, and forming at tlie iufcro-posteal corner a rounded projecting lobe, 

 posterior edge but slightly crenulated. Last pair of urojjoda of moderate 

 size, outer ramus rather broad, flattened, setons all rouud; inner ramus 

 small, scale-like. Telson with the lateral lobes comparatively broad and 

 blunted at the ti}), each with a single small apical spinule. Length of adult 

 female 8 mm. 



Remarks. — This new species may easily be recognized by its com- 

 paratively tumid body, tlie smooth urosome, and the unusually slight spinous 

 armature of tin; pereiopoda, which latter character has given rise to the 

 specific name. 



Description. — The length of fully adult, ovigerous specimens does not 

 exceed 8 mm. 



The body (see fig. 1 1 ) appears ratlun' robust and somewhat tumid, with 

 the back broadly rounded, and quite smooth throughout. 



The cephalon is but little longer than the 1st segment of the mesosome, 

 and has the lateral lobes rather broad and somewhat obliquely truncated, 

 with the inferior corner the more prominent. 



^-HS.-MaT. CTp. 281. 3 1 



