NATURAL SCIENCES OF PHILADELPHIA. 251 



Helix crispata, Pfr. (Eurycratem.) Am. Journ. Couch., VII. 179. 



Helix orbiculata, Fer. (DenteHaria.) Am. Journ. Conch., VI. 205, 

 pi. ix. rig. 14. Jaw apparently costate. 



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

 Jaw surely costate. 



Helix dentiens, Fer. (DenteHaria.) Am. Journ. Couch., VII. 179. 

 Jaw as in last. 



Helix perplexa, Fer. {DenteHaria.) Ann. Lye. N. II. of N. Y., X. 221. 

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

 ting edg&. 



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. (Caracolus.) Ann. Lye. N. H. of N. Y., X. 

 221. 



The species shown to belong to the Vitrininm. 



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

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



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

 Jaw with no anterior ribs. 



(c. ) WitJi jaw in separate pieces. 



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

 membrane. 



Liguus fasciatus, Mull. 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 s^ipplementary upper plate. 



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

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



PULMONATA LIMNOPHILA. 



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



Limnaea megasoma, Say. Am. Journ. Conch., VII. 162, pi. xii. fig. 3, (5. 



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

 Amer. 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. 



