368 6- 0. SAKS, 



Warpacliowsky in 3 different Stations of the North Caspian Sea. the first 

 (St. 54) located at some distance north of the islands Kulaly and Morskoj, 

 the 2nd (St. 58) lying North of the Tschistyi-Bank. and the Srd (St. 56) 

 occurring about midway between the 2 former Stations. 



In the collection of Dr. Grimm, only a single si)ecimen of this form was 

 found. It was, according to the label, taken off the west coast of Sara, among 

 Zostera. 



16. Gammarus obesus, G. 0. Sars, n. sp. 



(PI. XV). 



Specific Characters. — Body e.'sceedingly short and stout, with broadly 

 vaulted back. Lateral lobes of cei)lialon but slightly projecting, and evenly 

 rounded at the tij). Anterior pairs of coxal plates very large and fringed on 

 their distal edge with slender bristles; 1st pair rather widely expanded 

 distally; 4th pair not nearly as broad as they are deep. Epimeral plates of 

 metasome not very large, and scarcely produced at the lateral corners. Uro- 

 some short and stout, being quite smooth above. Eyes oval reniforni. Su- 

 perior antennae somewhat longer than the inferior, with the 1st joint of the 

 ]ieduncle rather large, flagellum a little longer than the peduncle, accessory 

 appendage comparatively small. Guathopoda in female not very strong, sub- 

 equal, in male somewhat larger and more unequal. All pereiopoda very 

 densely furnished with bristles, the 3 posterior pairs comparatively strongly 

 built, with the carpal joint rather short; basal joint of antepenultimate and 

 penultimate pairs of nearly same shape, with the infero-posteal corner not 

 at all produced; that of last pair very large and expanded, forming at the 

 infero-posteal corner a broadly rounded lobe. Last pair of uropoda unusually 

 short and stout, inner ramus minute, outer ramus setiferous in its outer part 

 only, terminal joint extremely small. Telson short and broad, each half with 

 only a single apical spine. Length of adult female 8 mm., of male 9 mm. 



Remarks. — The present new species is highly distinguished by its 

 unusually short and compact form of body, differing in this point con- 

 siderably from the Gammarid type, and approaching the species of the next 

 genus. It is moreover easily recognized by the densely hirsute and rather 

 strongly built pereiopoda, and by the poor development of the last pair of 

 uropoda. 



Description of the Temale. 



The length of an apparently adult specimen measures about 8 mm. 



The form of the body (see fig. 1) is extremely short and stout, indeed 

 more so than in any other known Gammarus, with the back broadly vaulted 

 and smooth throughout. 



■tus.-MaT, CTp. U48. gg 



