Achatinella and other Puhnonata. 345 



• 



more developed side cusps, which overlap the median cusps, 

 than in those from Dominica. 



The marginal teeth of the former exhibit a greater ten- 

 dency to splitting into sharp denticles on the cutting cusps 

 than those of the latter island. 



The Dominica lingual, in the only row counted, has 87-1- 

 87 teeth, one in the St. Kitts form has 57-1-57. 



These differences in the lingual membranes are noticeable, 

 but we believe, especially as the shells are identical, that 

 they are not of specific value. 



Ai»i»lail»iaMitts& (Siiccinea) riiljescefis, Dcsh. 



We are indebted to Governor Rawson for specimens (pre- 

 served in alcohol) of this species from Martinique. 



On examination of the jaw and lingual membrane, we 

 found that the species is not a Siiccinea, but an Amphibu- 

 lima* in which genus it is placed by Beck (Index, p. 98) 

 and by H. and A. Adams (Gen. Rec. Moll., 129), although 

 Pfeitfer treats it as a Snccinea and v. Martens (Die Ilclicecn, 

 ed. 2nd, 310) catalogues it in Succinea s. str.f 



The jaw agrees perfectly with that of the genus Amphibu- 

 lima described by us (Ann. L3'c. N. H. N. Y., X, p. 

 225, pi. xi, fig. 8). There are about sixty delicate ribs. 

 The lingual membrane has also the same general arrangement 

 as in that genus (I.e., fig. 9) with specific diflerences from 

 that of A. jmiula, especially in the widely expanded, blunt, 

 median cusp of the central tooth, and in the /6'Mcauert-like 

 cutting away of the lower margin of the teeth. The mar- 

 ginal teeth of A. rubescens resemble those we have figured of 

 Goeotis {I.e., pi. xi, fig. 7). 



A. rubescens occurs also in the environs of Cayenne 

 (Drouet, Moll, de la Guyane Frangaise, p. 49). 



*See our note on p. 345 of Journal de Conchjiiologie, XIII, Oct., 1873. 



t Since sending the above to the printer, we have received the Journal de Conchy- 

 liologie, 3d series, XIII, No. 4, Oct., 1873. On p. 324, is a description of the jaw and 

 anatomy of this species by Dr. Fischer, who suggests the subgeneric name lihudonyx, 

 overlooking its generic identity with Amphibulima. 



