120 



GAMMARID^. 



AMPniPODA. 



NATATOnU. 



LYSTANASSIDES. 



OALLISOMA CRENATA. 



Specific character. Inferior antenna' one-third the length of the animal. 

 First i)air of gnathopoda having the dactylos developed into a thick brush of 

 short hair. Fourth segment of the pleon having on the dorsaJ surfcice a deep 

 notch. 



Length, 5*^ inch. 



Callhoma crcnata. 



Scopelochewus crenaiiis. 



Spence Bate, Cat. Amph. Brit. Mus. p. 85, pi. 



xiv. fig. .'>. 

 Spence Bate, Brit. Assoc. Eep. 1855, p. 58. 



Synop. &c., Ann. Nat, Hist. six. 138 (1857). 



WaiTE, Hist. Brit. Crust, p. 167. 



This species is very round and smooth, and rolls itself 

 up almost into a ball. The head is small, and anteriorly 

 produced into a minute flat rostrum, which is merely a 

 projecting portion of the skin, extending horizontally witli 

 the top of the head. The antero-inferior angle projects 

 as far forwards as the extremity of the rostrum. The 

 eyes are small and reniform, showing black spots on a 



