May, 1S42.] 177 



ent name, which has neither priority nor sense to recommend it ; and which, 

 under other circumstances, this author would probably have rejected, if we may 

 judge from the fact that he adopts the names Physa and Planorbis, rather than 

 Bulinus and Coretus. The same principle would deprive Mr. Lea of all his spe- 

 cies of Alasmodon ; for assuredly authors will not adopt Shumacher's name (or 

 this genus, when so much a better one is in general use. Generic nomenclature 

 is not, and never has been, subjected to the rigid rule of priority which species 

 require; and a name founded upon the generic peculiarity will generally be adop- 

 ted in preference to others. A fossil animal with a head unlike that of a bird, was 

 named Omithocephalus ; it is now called Pterod ictylus. A remarkable mammal 

 with flat feet, and a bill like that of a bird, was first named Platypus, but is now- 

 known by the name Ornithorhynchus* alone. 



To put these matters to the test. I propose that the letter u shall take the place 

 of iv in the specific name of Unio Cowperianus of Lea, this gentleman having 

 committed an error in the orthography. To suit the views of those who do not 

 like the appearance of a name with the termination anus following a genitive, I 

 propose that Couperii be adopted instead of the above. There is an " Anodonta 

 Cowperiana" which I do not correct, because I wish merely to discuss a princi- 

 ple. I propose that all the species of the genus Alasmoiionj- or Alasmodonta, be 

 called by one of these names; and that the hybrid specific name of Unio Nash- 

 villianus be changed into the more correct and classical one of Nashvicensis. Fi- 

 nally, I disclaim all citation for these proposition*, as I think it would be the 

 height of absurdity to cite any one for species he does not know. 



In relation to the communication of Dr. A. Clapp, of New 

 Albany, Indiana, read March 8th, 1S42, the Committee con- 

 sisting of Mr. Conrad, Prof. Rogers and Mr. Vanuxem, re- 

 ported the following for publication in the Proceedings: 



A letter was read from Dr. A. Clapp of New Albany, Indiana, dated February 

 25ih, in relation to the Geological equivalents of the rocks of the Falls of the 

 Ohio, and other strata in the Western States. 



The author states, that, the'e appears to be little or no true carboniferous lime- 

 stone east of the Falls of the Ohio. The stratum which he doubtfully referred to 

 it, in a previous letter of December, 1840, viz the Oolitic and Pentremile lime- 

 stone of Professor Troost and Dr. Owen, he is now convinced is the carboniferous 

 limestone, commencing a short distance west of New Albany, and underlying the 

 coal formation in the western part of Indiana, part of Kentucky and Illinois. It 

 is entirely wanting in Ohio. 



He refers to his previous communication of April last, as showing that the 

 limestone of the Falls of the Ohio, the cliff limestone of Professor Locke, does 

 not belong to the Carboniferous, but to the Upper Siluiian System of Murchison. 

 The limestone of the Falls immediately underlies the black bituminous slate, 

 which appears to be the equivalent of the Marcellus shales of New York. The 

 lower strata of the Falls have many fossils of the Weulock limestone, but the 



* The middle h is sometimes omitted, as it was by Linneus in his genus Ryn- 

 chops. Is the first author who made the omission, and he who first wrote Rliyn- 

 chops, entitled to these genera, with their species ? In a notice of Kiener's work, 

 in the Re\U' Zoologique, this author is censured for writing " Pleurotonia mitrs% 

 formis Fell," Wond having previously used the specific name " mitrj'formis." 



j This ;s the more correct form, and corresponds with .Mono. Ion, Ifvodon, Dio- 

 don, etc. 



