460 «. 0. SARS, 



angnlarl}- bent in tlie middle, and are obtusely truncated at the tip. They 

 carry each a single apical spinule, and a similar lateral one. 



Occurrence. — Some few specimens of this form, for the greater part 

 still immature, are contained in the collection of Dr. Grimm, having been 

 collected partly in the bay of Baku, from a depth of 2 — 6 fathoms, partly 

 in the middle part of the Caspian Sea, from a de])tli of 40 fathoms. A soli- 

 tary, quite young, male specimen was taken last year by Mr. Maxiraowicz 

 in the bay Karabugas. 



17. Gammarus platycheir, G. 0. Sars, n. sp. 



(PI. 8, figs. 14—27). 



Specific Characters. — Body rather robust and tumid, with broadly 

 vaulted back. Lateral lobes of cephalon transversely truncated at the tip. 

 Anterior pairs of coxal plates rather deep, and densely fringed with bi'istles; 

 1st pair tapering couically, 2nd pair likewise narrowed distally, 3rd pair 

 oblong quadrangular, 4th pair rather broad, forming beneath the posterior 

 expansion an angular corner. Last pair of epimeral plates of metasome but 

 slightly jiroduced at the lateral corners. Urosome with a few scattered 

 spinules above. Eyes oblong reniform. Antennae very short, the superior 

 ones not exceeding in length the inferior, and having the flagellum shorter 

 than the peduncle, accessory appendage 4-articulate. Gnathopoda very un- 

 equal, the posterior ones being much stronger than the anterior, with the 

 propodos greatly expanded distally, palm arcuate, and having a dense series 

 of submargiual bristles, detining angle very slight, spinous, one of the 

 spines being much elongated, dactylus long, falciform. Pereiopoda rather 

 slender, basal joint of last pair much larger than that of the 2 preceding 

 pairs, oblong oval, hind edge densely setiferous. Last pair of uropoda not 

 much elongated, outer ramus subfoliaceous, fringed with setae, inner rather 

 small. Telson cleft nearly to the base, lateral lobes obtusely pointed, and 

 each armed with 3 small apical spinules. Length 16 mm. 



Remarks. — This is a rather anomalous form, which is only provisionally 

 placed under the genus Gammarus, exhibiting, as it does, some points of 

 aftinity both to the genus h'ipliargoides and to Pandorites. 



Description. — The solitary specimen examined, which seems to be of 

 male sex, measures about 16 mm. in length, and is accordingly of rather 

 large size. 



The body (see tig. 14) somewhat resembles in form that of the species 

 of the genus Niphnrgoidcs, being rather robust and tumid, with the back 

 broadly vaulted and quite smooth. 



*ii3.-5IiiT. orp. 280. 40 



