214 G. M. Giles — Six neio AmpMpods from the Bay of Bengal. [Ko. 2, 



itself ; and to tlie genus, as thus limited, neither of my forms can be 

 said perfectly to agree. 



To the less limited genus of Spence Bate, however, one of them 

 corresponds in every point, but it differs from the genus as defined by 

 Glaus in the following points : — 1st., in my one female specimen, I can 

 make out no trace whatever of inferior antennae ; 2nd., the subchela of the 

 '' 5th " (6th) thoracic appendage cannot be said to be slender, the fixed 

 ramus being very stout and almost quadrate ; 3rd., there are two extra 

 small gill-sacs on the 2nd and 3rd thoracic segments, a character ex- 

 tremely abnormal, but of the reality of which I carefully satisfied myself. 

 To avoid, however, the necessity of manufacturing a new genus, I 

 describe it as a member of the genus Phronima, as defined by Spence 

 Bate, under the name of P. hucepTiala. 



With the second of the species to be described the case is differ- 

 ent, as it will not fit into any genus, whether the Phronima of Spence 

 Bate, or the genera distinguished by Glaus, namely, Phronima^ Phroni- 

 mella, Phronimopsis, and Paraphronima. Of these the species comes 

 nearest to the definition of Phronimella, which is thus given by Glaus : — 



" Body much produced, entirely transparent, with but two pairs of 

 style-shaped uropods, head short, with high-arched upper surface, 

 vertico-oral axis much produced. The two front segments united 

 without suture. Mandibular palps wanting even in the male. Tongue 

 (Zunge) of the maxillipedes reduced to a wart-like excrescence. Both 

 pairs of gnathopods slender with weak apposed subchelse. The third 

 pair of thoracic appendages somewhat smaller, the fourth much pro- 

 duced. The fifth pair of legs with a much produced apposed pair of 

 subchelse. Three pairs of gill-sacs on the 4th, 5th, and 6th thoracic 

 segments." 



With this definition, the specimen agrees in the very important 

 detail of possessing but two pairs of style-shaped uropods, and in nearly 

 every other item save in this that, in our species, the " 3rd " (4th) 

 thoracic appendages have the unfortunate peculiarity of being the longest 

 and almost the largest of the whole series, instead of being smaller. A 

 minor difference is that the two first thoracic segments, although united, 

 shew signs of a short, but perfectly distinct, suture between their pleura. 



On this account, one is reduced to the alternatives of either widen- 

 ing the range of Phronimella by cutting out the character referring to 

 the third thoracic agpendage, or of making a new genus. The making 

 of new genera is an expedient which should, I take it, be avoided when- 

 ever possible, so that I prefer to adopt the former alternative and to 

 describe the species as Phronimella hip^pocephala. 



I will now proceed to the description of the two species. 



