! NATURAL SCIENCES OF PHILADELPHIA. 3 



Operculum ovate, light-brown, rather thin, having several volutions, and 

 with the polar point well removed from the left margin. 



II ib. Wabash River, Indiana, H. C. Grosvenor. 



Remarks. I have thirte j n specimens of this remarkable shell. Eight of them 

 have a well-defined though delicate notch on the edge at or near to the peri- 

 phery of the last whorl. Five of the specimens hava no notch, which pro- 

 bably arises in four of them from not being full grown, and in one from having 

 the thin, delicate edge broken off. In all the specimens there is a light line 

 under the sutures, and some have six or seven brown bands, which are dis- 

 tinctly seen on the inside. The channel at the base is small but well defined. 

 In outline, this species reminds oae of GoniobasU Vauxiana (nobis) and Mela- 

 nin (Goniobasis) germana, Anth. It is a thinner shell than either, and the notch 

 in the lip removes it from that genus. The aperture is about one-half the 

 length of the shell. I have great pleasure in uaming this species after Mr. 

 Grosvenor, to whom I am greatly indebted for miny of our Western Mollusca. 



Descriptions of eleven new Species of Indigenous MELANIDJE. 



BY ISAAC LEA. 



Goniobasis Emeryhnsis.* Testa, plicata, subfusiformi, subtenui, tenebroso- 

 oliva,. evittatj, ; spira, obtuse conoidea ; suturis irregulariter impresses; an- 

 fraciibus instar senis, planula-tis, superne plicatis ; apertura. grandiuscuhi, 

 subovata, intus cseruleo-alba; labro acuto, leviter sinuoso ; columella inferne 

 parum incrassn.ta, et contorta. 



Operculum ovate, dark- brown, with polar point near to the base. 



Hab. Rocky Creek, head branch of Emery Run, E. Tennessee, Major S. S. 

 Lyon, U. S. E. 



Goniobasis umbonata. Testa nodulata, subfusiformi, subcrassa, obsolete 

 vittata, tenebroso-oliva ; spira valde obtu=>a ; suturis valde impressis ; an- 

 fractibus irregulariter umbonatis, subsuturis tumidis, ultimo pergrandi ; aper- 

 tura pergrandi, subelliptica ; labro acuto, leviter sinuoso ; columella superne 

 iucrassata, inferne subsinuosa. 



Hab. Smith's Shoals, Cumberland River, E. Tennessee, Major S. S. Lyon 

 U. S. E. 



Remarks. This is the fourth species of a natural group which I have de- 

 scribed, and which have a large ear-shaped aperture, viz.: Melania [Gonio- 

 basis) basalis, Midas, gibberosa and now umbonata. If they be not entitled to a 

 generic place, they may at least be considered a subgenus, for which I propose 

 the name of Eurycxlon, from Kugoc, amplus, and Kctxcv, cavilas, the aperture 

 being larger than in the Melanidse generally. All the species of Eurycie- 

 lon have a callus on the columella above, but not below, as in Lithasia, and 

 the base is more or less angular, which is not the case with Anculosa. Those 

 which we have considered as varieties of Anculosa preerosa, Say, which have 

 an angular base, properly belong, I think, to Eurycxlon as well also Anthonyi, 

 Redfield, turbinata, and tintinnabulum (nobis), and some others. When the 



* In my paper on New Melanidse. of the United States, published in the Proceedings of the 

 Academy, in 1S61, and more at large in the Journal, vol. v. and in my Observations, vol. ix. I 

 used the names of blanda and Vanuxe.mii for two new Goniobasi. Haviug used both names 

 before as Metanise, which now come under the genus Goniobasis, I propose to change blanda into 

 versa and Vanuxemii into Presloniana, the former, Vanuxemii, having been found at Col. Pres- 

 ton's salt works in Western Virginia. 



Mr. Raeve having published in his "Conchologia Iconica" Melania (Goniobasis) Canbyi (nobis) 

 under the name of ' Etowaliensis, Lea." prior to my publication of it. the name of Etowahensit 

 must be retained for that species. I therefore transfer the name of Canbyi to the speeits which 

 i subsequently published as Etowahensis in the Jour. Acad. Nat. Sfci., vol. v. and" Observations " 

 vol. ix. pi. 37, fig. 133. 



1834.] 



