NATURAL SCIENCES OF PHILADELPHIA. 251 



Helix crispata, Pfr. {Eurycratera.) Am. Journ. Concli., VII. 179. 



Helix orbiculata, Fer. {Dentellaria.) Am. Journ. Conch., VI. 205, 

 pi. ix. fig. 14. Jaw apparently costate. 



Helix Isabella, Pfr. (Dentellaria.) Am. Journ. Conch., VII. 179. 

 Jaw surely costate. 



Helix dentiens, Fer. (Dentellaria.) Am. Journ. Conch., VII. 179. 

 Jaw as in last. 



Helix perplexa, F^r. (BenteUana.) Ann. Lye. N. H. of N. Y., X. 221. 



Jaw with traces of anterior ribs, but with a median projection to its cut- 

 ting edge. 



Helix Schroeteriana, Pfr. (Pleurodonta.) Am. Journ. Conch., VII. 

 179. 



Lingual membrane alone examined. 



Helix acuta, Lam. (Pleurodonta.) Am. Journ. Conch., VI. 204. 



Helix excellens, Pfr. (Garacolus.) Am. Journ. Conch., VII. 180. 



Lingual membrane only examined. 



Helix Bermudensis, Pfr. (Garacolus.) Ann. Lye. N. H. of N. Y., X. 

 221. 



The species shown to belong to the Vitrinin(E. 



Helix fuscocincta, Ad. (Leptoloma.) Am. Journ. Conch., VII. 180. 



Jaw unlike generic description in having a median projection and no ribs. 



Helix PhcBnix, Pfr. (Acavus.) Am. Journ. Conch., VII. 180. 



Jaw with no anterior ribs. 



(c. ) With jaw in separate pieces. 



Liguus virgineus, Lin. Am. Journ. Conch., VI. 209, fig. 3, 4, lingual 

 membrane. 



Liguus fasciatus, Miill. Am. Journ. Conch., VI. 211, pi. ix. fig. 6. 



Orthalicus zebra, Miill. Am. Journ. Conch., VI. 212, pi. ix. fig. 2. 



Orthalicus undatus, Brug. Am, Journ. Conch., VI. 213, pi. ix. fig. 10, 

 12. 



(d.) With jaw with supplementary upper plate. 



Succinea effusa, Shuttl. Am. Journ. Conch., VI. 213, pi. ix. fig. 15. 

 Succinea Nuttalliana, Lea. Ann. Lye. N. H. of N. Y., IX. 282, fig. 1. 



PULMONATA LIMNOPHILA. 

 Limnaea appressa. Say. Am. Journ. Conch., VII. 161, pi. xii. fig. 1, 2, 5. 

 Limnaea megasoma. Say. Am. Journ. Conch., VII. 162, pi. xii. fig. 3, 6. 

 Pompholyx effusa, Lea. Ann. Lye. N. H. of N. Y., IX. 290, fig. 9.— 

 Araer. Journ. Conch. VI. 312, pi. xviii. 



Planorbis trivolvis, Say. Ann. Lye. N. H. of N. Y., IX. 292, fig. 10. 

 Melampus bidentatus, Say. Ann. Lye. N. H. of N. Y., IX. 286, fig. 7. 



