SUCCINEA. (55 



but a species which was imknown to him. As, how- 

 ever the ovalis of Gould is that now most commonly 

 known under the name of Succinea ovalis, we propose 

 to retain it, and to apply to Mr. Say's species, his 

 second name, ohliqua. 



Succinea avara, Say. The received opmion is, that this 

 is a well-established species, founded, however, on a 

 young shell, and that the mature shell was afterwards 

 characterized by Mr. Say, as Succinea vermeta. We 

 propose to retain for it the earHest name, avara. 



Succinea undulata, Say, is a Mexican species, of which 

 specimens do not exist in our cabinets. Judging by 

 the description alone, it may prove to be a variety of 

 Succinea ovalis, Say. 



Mr. Isaac Lea of Philadelpliia has published the fol- 

 lowing descriptions of North American Succinea. 



Succinea retusa. Testa ovata, oblonga, tenuissima, pellucida, 

 flavidula ; spira brevi, anfractibus binis ; apertura inferne 

 dilatata et retracta. Hab. Ohio. Diameter, .3 ; length .7 

 of an inch. 



Succinea aperta. Testa sub-rotunda, tenui, flavescente, Isvi; 

 spira brevissitna ; anfractibus binis, ultimo grandissimo ; 

 apertura lalissima. Hab. Banks of Columbia river. 



Succinea wardiana. Testa obliquo-ovata, sub-nitida, diaphana, 

 obsolete striata, lutea ; spira breviuscula; suturis sub-im- 

 pressis ; anfractibus ternis convexis ; apertura sub-rotunda. 

 Hab. Ohio. 



Swxinea toUeniana. Testa obliquo-ovata, sub-nitida, sub-diaph- 

 ana, obsolete striata, cornea ; spir4 brevi ; suturis impressis ; 



VOL. II. 17 



