224 



AMPHIPODA. 



NATATORIA. 



GAMMARIDJ;. 



PHOXIDES. 



OTUS CARINATUS. 



Specific character. Pereion furnished with a dorsal carina. Third seg- 

 ment of the pleon hav-ing an elevation near the dorsal centre, and the 

 posterior margin produced into a sharp tooth near the centre on each side. 



Length 5^3 inch. 

 Otus carinatus. Spenoe Bate, Cat. Crust. Amph. Brit. Mus. p. 126, pi. 

 xxiii. fig. 2. 



The head is very short, but produced anteriorly to a 

 sharp point, slightly depressed. The back is furnished 

 with a small but distinct median carina. The third seg- 

 ment of the tail is abruptly elevated near the middle, 

 and again gradually depressed to the posterior margin. 

 On each side the posterior margin is posteriorly pro- 

 duced, near the centre, into a long slightly-upturned 

 tooth. The eyes have not been observed. The superior 

 antennae are short, being scarcely more than twice the 

 length of the upper margin of the head ; the perluncle 



