462 ANNELIDES. 



The SiGALioNES, Aud. and Edw., have a much more elongated 



form than the other Aphroditae; each foot is furnished with cirri(l). 



The AcoETES, Aud. and Edw^, are provided with cirri which 



alternate with the elytra(2); their jaws are stronger and more deeply 



dentated. 



A large species is found at the Antilles which inhabits a tube 

 of the consistence of leather(3). * 



This is the only situation we can assign to a new and very 

 singular genus which I call 



t 



Ch^topterus, Cuv. 



The mouth has neither jaws nor proboscis, and is furnished above 

 with a lip to which are attached two tentacula. Next comes a disk 

 with nine pairs of feet, followed by a pair of long silky fasciculi re- 

 sembling wings. The lamellated branchiae are rather beneath the 

 body than above it, and extend along its middle. 



Chastopterus pergamentaceus, Cuv. This species, which is 



found at the Antilles, is from eight to ten inches in length, and 



inhabits a tube resembling parchment(4). 



(1) Sigalion Mathildas, Aud., and Edw., Littor. de la France, Annel. 



(2) Acoetes Pleei, Aud., and Edw., Collect, of the Museum. 



(3) N.B. The Phyllodoce maxillosa of Jianzani, called Polyodon-te by Rein- 

 ier], 3iV\d Eumolpe maxima by Oken, seems to be closely allied to the Acoetes; its 

 proboscis and jaws are the same, and neither of the genera has, perhaps, been 

 described from perfect specimens. 



There remain various Annelides so imperfectly described that we are unable to 

 characterize them well; such are the Nereis cseca, Fabr., Soc. Hist. Nat. Copen. 

 parti, pi. iv, f. 24 28; iV. longa. Id., lb., f. 11 13; iV. aphroditoYdes, lb., 

 4 7; lb., 11 13; Branchiarius quadrangulatus, Montag., Lin. Trans., XII, pi. 

 xiv, f. 5-,Diplotes hyalina, Id., lb., f. 6 and 7; and the pretended Hirudo Iran- 

 chiata, Archib. Menzies, Lin. Trans. I, pi. xvii, f. 3. I have also omitted the 

 Myhian^ and two or three other genera of M. Savigny, on account of my having 

 had no opportunity to re-examine them. 



(4) It will be more minutely described by Messrs Aud., and Cuv., in the An- 

 nales des Sciences Naturelles. m 



