. Genera of Terrestrial MoUusca, etc. 203 



many species of North American Sttccinea, we think erro- 

 neously, to BracJiyspira. In Land and Fresh Water Shells 

 of JVbrth America (18G9) we adopted the hitter in the sense 

 in which it is used by Albors (ed. 2). 



©BMstloisys D'Orb. 



Albers {I. c, 311) refers to O. unguis Fer. as the tjq^e of 

 this group. D'Orbigny (Voy., 229, t. 22, figs, 1-7) gives 

 the following description of the animal : 



"Allonge, ovale, depnme, beaucoup trop grand pour rentrer dans la 

 coquille, occupant pres de trois fois la surface de celle-ci; pied tres large 

 debordant de toutes parts, arrondi enavant, acumiue posterieureraent, lisse 

 en dessous et endessus; raanteau formant uu bourrelet autour de la 

 coquille, qu'il recouvre sur les bords, etroit en urriere, plus large et comme 

 plisse en avaiit; col assez long; tete etroite ; tentacules courts; oriflce 

 des poumons sous le bord droit du nuuiteau, vers sa partie moyenne." 



Fischer (Melang. Conch., p. 67, pi. vi, f. 1) describes the 

 animal of 0. unguis and its dentition. 



Sometime since we were indebted to Mr. John G. Anthony 

 for specimens collected by him (Agassiz' expedition) in 

 Brazil, and found, on examination of the jaw and lingual 

 dentition, that both agree with the figures given by Heyne- 

 mann (Mai. Blatt., 18G8, taf. iv, fig. 5) of the jaw and teeth 

 ot PellicLda convexa Martens, of which figures we add copies 

 (plate ix, figs. 12-14). 



. As already mentioned, we have lately received from Gov- 

 ernor Rawson specimens in alcohol of animal and shell of 

 O. unguis, collected in Guadeloupe by Schramm, and find 

 that both jaw and teeth are precisely similar to those of the 

 Brazilian examples. 



It appears, irrespective of form of animal and shell, that 

 should even Amphibulima prove like Onialonyx to be elas- 

 mognathous, the lingual dentition of the latter does not 

 warrant its being treated, as proposed by Guppy, as a section 

 of the former genus. 



Guppy has lately discovered in Trinidad, but not yet, we 



