SCALPELLUM. 



TESTA tredecim-valvi, lateraliter compress^, 

 pedunculo brevi squamoso affixa, valvis con- 

 tiguis, inaequalibus, utroque latere basalibus 

 tribus minoribus, superioribus duabus superne 

 acuminatis, intermedia unica trapeziformi, 

 dorsali elongata, apiee acuminate, dorso 

 angulato. 



ScALPELLUM is another genus of Cirripedes which Dr. 

 Leach has separated, and we think rightly, from Lamarck's 

 Anatifa (now called Pe7itelasmis under circumstances which 

 we have formerly explained.) At present we are only 

 acquainted with two species belonging to this genus^ both 

 of which are recent, one of them not uncommonly found 

 adhering to Sertularia antennina ou the coasts of Britain 

 and the other from the straits of Magellan. 



In form Scalpellum approaches to Pentelasmis, being 

 laterally compressed and acuminata at the upper extremi- 

 ty; it consists of thirteen valves, six on each side and one 

 dorsal; it is affixed by a short squamose peduncle. The 

 valves are contiguous, united together by a sort of carti- 

 lage, they are unequal, the three basal (on each side) 

 being smaller than the rest, the two upper being acuminated 

 at their upper extremity and the single central one trape- 

 ziform. The dorsal valve is elongated, acuminated at the 

 apex and angular on the back. 



It may not be improper here to draw the attention of 

 our readers to the subject of the true nature of the Cirri- 

 pedes in general. It will be observed that they are entitled 

 to a place in this work because by common consent they 

 have been considered as Shells ; and in speaking of Pente- 

 lasmis we have shown that according to Lamarck, they 

 partook of the characters both of the Mollusca and the 



