OF CONCHOLOGY. 



175 



exoleta (and perhaps includes albolabris, etc.), while Aphdon 

 may have been founded on tliyroides and other umbilicate 

 species.* 



Very respectfully, 



J. G. Cooper, M. D. 



The following papers were read and referred to committees : 



"Notes on the Land Shells of Trinidad," &c. By Thomas 

 Bland. 



" Description of a new species of Sepioteuthis from the West 

 Indies." By Wm. M. Gabb. 



"Description of a new Conus from Florida." By Wm. M. 

 Gabb. 



" Descriptions of Fossils from the Clay Deposits of the Upper 

 Amazon " By Wm. M. Gabb. 



"Catalogue of the Family Anatinidre." By T. A. Conrad. 



" Notices and Reviews of new Conchological Works." By 

 George W. Tryon, Jr. 



" Catalogue of the Family Tellinidre ; Part 1. Sub-family 

 TellininEe." By George W. Tryon, Jr. 



Mr. Tryon, on behalf of the Publication Committee, announced 

 that a sufficient number of subscribers to the new edition of 

 Haldeman's Monograph of Fluviatile Mollusca, and the continua- 

 tion thereof, had been received, to secure the publication of those 

 works. 



Mr. Wm. M. Gabb called attention to a remarkable case of 

 obliquity in an Ammonite. The specimen in question is from 

 the Jurassic rocks of Volcano, Nevada ; it has the numerous 

 whorls and square cross-section so common in Liassic species, 

 and is tricarinate on the dorsum. The siphuncle, instead of 

 being in the median line, is in the right hand dorso-lateral angle ; 

 it carries with it the dorsal lobe, the ventral lobe being on the 

 left hand umbilical angle. The peculiarity is shown on pi. 16, 

 fig. 8, 8a, fig. 8 being a view of the broken end of a whorl show- 

 ing the face of a septum, and fig. 8a being a diagram of the sep- 

 tum d, dorsum, s, siphuncle, tv, w, umbilical angles. There is a 

 marked difference in size between the corresponding lateral 

 lobes. 



* Note. — I think Dr. Cooper is wrong in referring shells like profunda 

 to Mesodon, because Kafinesque states, in his description of that genus, 

 that Odomphium differs in having "an ombilic." It is therefore proper 

 to infer that in Mesodon there is none, i. e., it is covered. Besides, ac- 

 cording to my recollection, not having it to refer to (although not quo- 

 table in determining the genus), Rafinesque's Conchologia Ohiensis in 

 MSS., contains a fiyure in ink of Mesodon which is an albolabris. — 

 Editor. 



