262 AMPIIII'ODA NOKMALIA. 



5. CERAPUS. 



Ceramis, Say, Jouni. Acad. PhilaiL i. p. 40. 



I)esmarest, Consul, sur Ics Crust, p. 271. 



FAhvards, Ann. des Sci. Nat. xx. p. ,'582. 



Tonp/rtou, Trans. JEut. Soc. i. p. 188. 



miitc, Hist. Brit. Crust, p. 189. 



Gosse, 3Ian'?H' Zool. i. p. 140. 

 Erichthonius, Edivards, Ann. dcs Sci, Nat. xx. p. 383. 



Spvnce Bate, Brit. Assoc. Beport, 1855 ; Synopsis, SfC, Ann. Nat. 

 Hist. Feb. 1857. 



Hldte, Hist. Brit. Crust, p. 196. 

 Corapodiiia, Edwards, Hist, des Crust, iii. p. 62. 

 Pyctilns, Dana, U. S. Explor, Exped. p. 973. 



Not laterally compressed. Coxae not more than half as deep as their 

 respective segments of the body. Antennae siibequal ; peduncles 

 longer than the flagcUa. First pair of gnathopoda complexly* 

 snbchelate : second pair mnch larger than the first ; dactyla an- 

 tagonizing with a prominent process on the carpus. Fii'st three 

 pairs of pereiopoda short and robust, last two long. Posterior pair 

 of pleopoda robust, single-branched, ramus terminating in two 

 small hooks. Telson bilobed, each lobe crowned with several rows 

 of curved teeth, the points of which are directed upwards. 



Mibie-Edwards founded the genera Erichthonius and Cerapoclina, 

 with articulated flagella to the antennoD, in order to distinguish them 

 from Cerapus, in which, according to Say, the flagella consist of a 

 single joint (a not unusual term with some authors even when they 

 are articulated), and on account of some inaccuracies in Templeton's 

 description and figure of Cerapus ahditus. Dana's separation oiPyctilus 

 from Erichthonius depends chiefly upon the figure of E. difformis in 

 the ' Hist, des Crust.' being di-awn Avith the coxa; of the gnathopoda 

 fused with the segments of the pcrcion — which, Professor MUne- 

 Edwards informs me, is owing to an error of his artist. It is for 

 these reasons that I consider the genera Erichthonius, Cerapoclina, 

 and Pyctihis, together with Bercothoe, as merely synonyms of Cerapus. 



1. Cerapus tuhularis. (Plate XLV. fig. 1.) 



Cerapus tubularis, Say, Journ. Acad. Philad. i. p. 49. pb 4. f. 7-11. 

 Edwards, Ann. des Sci. Nat. xx. p. 382. 

 Desmarest, Consid. sur les Crust, p. 271. 



" Cephalon having a mucronate carina before. Eyes oval, black, 

 hardly prominent. First pair of gnathopoda with the propodos 

 smaU, ovate ; dactylos not closing on the propodos : second pair 

 having the carpus large, triangulate, the infero-distal angle being 

 produced to a point ; propodos narrow ; dactylos shorter than the 



* By this term I mean, whenever the chelate character depends upon other 

 joints than the pi'opodos. 



