222 CRUSTACEA. 



ticulated ; those of the second pair consisting of a single and long 

 joint*. 



Cekapus, Sai/. 



Large antennae, the peduncle consisting of three — the superior — 

 or four — the inferior — joints ; the two anterior feet small, Avith a 

 uni-articulated toe ; the two following terminating in a large triangu- 

 lar, smooth, dentated hand, with a bi-articulated finger. 



Ceraphus tubularis. Say, Journ. Acad. Nat. Sc. of Philad., I, 

 iv, 7 — 11 ; Desmar., Consid., XLVI, 2. It inhabits a little cy- 

 lindrical tube, and in this respect approaches the subsequent 

 subgenus. Very common at Egg Harbour, New Jersey, among 

 the Sertvdarise on which it appears to feed. 



Finally, the inferior antennae, sometimes much larger than the 

 superior, their stem consisting at most of four joints, have the form 

 of feet, and appear to serve, at least occasionally, as organs of pre- 

 hension. 



Here the second feet are terminated by a large forceps. 



PoDocERTjs, Leach. 



Eyes very prominent f . 



Jassa, Leach. 



Eyes not prominent \. 



There, neither of the feet is terminated by a large forceps. 



CoROPHiuM, Lat. 



C. longicornis ; Cancer grossipes, L. ; Gammarus lonqicornis, 

 Fab. ; Oniscu.s volutator, Pall., Spic. ZooL, Fascic. IX, iv, 9 ; 

 Desmar., Consid., XLVI, 1, called Peryns, on the coast of Ro- 

 chcUe, lives in holes, whicli it forms in the mud, that is covered 

 with hurdles, called bouchots, by the inhabitants. The animal 

 does not make its appearance till the beginning of May. It wages 

 everlasting war against the Nereides, Amphinomse, Arenicolae, 

 and other marine Annclides, which inhabit the same locality. A 

 curious spectacle is presented by these Crustacea, Avhen the tide 

 is coming in ; myriads of them may then be seen moving in every 

 direction, beating the mud with their great arms, and diluting 

 it in order to discover their prey — is it one of the above men- 

 tioned Annelides they have discovered, Avhich is ten or tAventy 

 times larger than themselves? they unite to attack and devour 

 it. The carnage never ceases until the mud has been thoroughly 

 turned up and its inequalities levelled. They do not even 

 spare Mollusca, Fishes, or dead bodies on the shore. They 

 mount upon the hurdles which contain Muscles, and fishermen 



* Cancer articulosus, Montag., Trans. Lin. Soc. VII, 6 ; Desmar., Consid., p. 

 263, XLV, 5. 



•f Podoeerus variegatus, Leach, Trans. Lin. Soc, XI, p. 361 ; Desmar,, Consid., 

 p. 269. 



X Jasia pulcheUa, Leach, lb., p. 361 ; Desmar., Consid,, p. 269. 



