58 PROCEEDINGS OF THE ACADEMY OP 



Pleurodonta The jaw in Ghemnitziana ^ Pfr. (ante, p. 51) has 



T stout, seijarated ribs ; Carmelita, Few has 6 (ante, p. 51); acuta. 

 Lam. (Amer. Journ. Conch., VI. 204) has 1 ribs. 



Tlie linoual membrane is the same as I fio-nre for Carmelita 

 (plate X., fig. 5) in Schroteriana (Amer. Journ. Conch., VII. 179), 

 in invalida, Ad. (Ann. N. Y. Lj-c, x. ITO). In acuta^ Lam. the 

 centrals and laterals are of the same type, but the marginals have 

 only one long, wide, blunt denticle, slightly bifid at end. In this 

 respect it is more like Caracolus than the other species of Pleuro- 

 donta examined by us. 



Caracolus. We have shown H. Bermudensis, Pfr. (Ann. N. Y. 

 Lye, X. 221) to belong to Vitrininse ; H. inversicolor (1. c. x. 169) 

 to Nanina. 



The jaw in H. marginella^ Gmel. (ante, p. 51) appears to be 

 ribbed. 



I figure (plate X,, fig. G-T) the lingual dentition of H. excel- 

 lens, Pfr. (Am. Journ. Conch. VII. 180). H. marginella, Gmel. 

 agrees with it, excepting that the cusps of the marginals are 

 shorter. 



Leptoloma. We have described only H. fuscocincta, Ad. (Am. 

 Journ. Conch., VII. 180). The jaw has a median projection, but 

 no ribs. Tiie lingual I figure on plate IX., fig. 9. 



Acavus. H. phcenix^ Pfr. has a ribless jaw (Am. Journ. Conch., 

 VII. 180). Its dentition is figured on plate IX., fig. 11. 



In Bulimus we have examined the following genera: 



Macrodontes we know by B. odontostomos (Am. Journ. Conch., 

 VI. 209). The jaw is ribless. The dentition is figured on plate VI., 

 fig. 1. 



Pelecychilus we know from B. au7'issileni, Born (Ann. Lye. N. 

 H. N. Y., X. 229), and B. glaber, Gmel. (not before published) ; both 

 have delicate ribs as in Bulimulus, Cylwdrella, etc. The denti- 

 tion of the former is given on plate VI., fig. 4 ; of the latter on 

 plate VI., fig. 6. 



Anihinus we know from B. multicolor^ Rang (Am. Journ. 

 Conch., VI. 208). The jaw is ribless. Lingual dentition given on 

 plate VI., fig. 8. 



Pachyotus we know from B. egregius, Jay (see this paper, p. 54). 

 Jaw not examined. Lingual dentition figured on plate VI., fig. 1. 



Bonis. We have examined B. oblongus^ Mull. Its ribbed jaw 

 and lingual dentition are figured by Heynemann (Mai. Blatt., xv.). 



