452 COROPHIID^. 



A MPHIP ODA P ODOC BRIDES. 



NATATORIA. 



Genus CERAPUS. 



Cerapus. SAY, Journ. Acad. Philad. i. p. 49. DESMAREST, Consid. sur 

 Crust, p. 271. MILNE EDWARDS, Ann. des Sci. Nat. 

 xx. p. 382. TEMPLETON, Trans. Ent. Soc. i. p. 188. WHITE, 

 Pop. Hist. Brit. Crust, p. 189. GOSSE, Mar. Zool. i. 

 p. 140. SPENCE BATE, Cat. Amph. Brit. Mus. p. 262. 



Ericthonius. MILNE EDWARDS, Ann. des Sci. Nat. t. xx. p. 383. Hist, des 

 Crust, t. iii. p. 59. SPENCE BATE, Rep. Brit. Assoc. 1855, 

 p. 59. Ann. Nat. Hist. 2 ser. xix. p. 149. WHITE, Pop. 

 Hist. Brit. Crust, p. 196. 



Cerapodina. MILNE EDWARDS, Hist, des Crust, iii. p. 62. 



Pyctilus. DANA, United States' Explor. Exped. p. 973. 



Generic character. Body not laterally compressed. Coxae 

 not so deep as their respective segments of the body. Antennae 

 subequal : superior pair furnished with a secondary appen- 

 dage; inferior antennae having the flagellum multi-articu- 

 late. First pair of gnathopoda subchelate : second pair of 

 gnathopoda large, complexly subchelate. Posterior pair of 

 pleopoda unibranched. Telson rudimentary, supporting nu- 

 merous small, sharp points. 



IN this genus the body of the animal is not deep 

 or laterally compressed. The antennae are nearly of the 

 same length, although the lower are the more powerful 

 pair of organs. The flagella are multi-articulate. The 

 first pair of hands are simply subchelate ; the second 

 pair have the wrist largely developed and inferiorly pro- 

 duced so as to antagonize at its extremity with the apex 

 of the finger. All the walking legs have the thighs 

 equally dilated. The posterior pair of caudal append- 

 ages are single-branched, and the middle piece is bilobed, 

 each lobe being studded with minute, sharp, anteriorly- 

 directed teeth. 



