300 THE GENUS REMONDI A— STANTON. 



In 1887 Dr. C. A. White' described the genus Stearnsia and referred 

 it to the CrassatellidiX', the type being Stearnsia robhinsi, from the 

 Comanche series near Fort Worth, Texas. As it diftered greatly from 

 RemomVia furcata in outline and showed no relationship with Trigonia 

 no comparisons with Gabb's genus were suggested. 



When examining the types of RemoiuUa in the Academy of Natural 

 Sciences, Philadelphia, a short time ago, my attention was attracted to 

 their striking resemblance to Stearnsia in surface sculpture, form of 

 lunule and escutcheon, and other external characters. Through the 

 courtesy of the Curators of the Academy I have been permitted ti> 

 study these types more closely and to make direct comparisons with 

 the types of Stearnsia in the United States National Museum. 



The study of the specimens has sliown some errors in the original 

 description of Rcmondia, especially in the details of the liinge, that 

 have prevented the genus from being understood. 



The cardinal teeth were clearly seen by Gabb in only one fragmen- 

 tary si)eeimen, which he described and hgured as a left valve, but 

 which is really a right valve, as the lines of growth and position of 

 the ligament show. It has three cardinal teeth as described, but the 

 hinge of the left valve when cleaned shows only two cardinals, thus 

 agreeing with Stearnsia. The striation of the cardinal teeth, which 

 seems to have been the i>rincipal reason for referring the genus to the 

 Trigoniida', is precisely like that seen in many species of Crassatella 

 and Astarte — CrcssaieUa radosa, Morton, for example. There is a long 

 slightly rugose posterior lateral lamina or tooth in the left valve and a 

 similar anterior one in the right valve, with corresponding sockets 

 opposite them. This also agrees essentially with Stearnsia, though in 

 the original descrijjtion of that genus the structure here designated as 

 a socket is regarded as two lateral teeth. The character of the lateral 

 laminie is precisely like that seen in some species of Crassatella, such 

 as Crassatella umlnlata, Say, from the Miocene, excepting that their 

 positions are reversed, the right valve of the Crassatella bearing the 

 posterior lamina and the left valve the anterior one. 



The ligament, instead of being external as described, was partly 

 internal, and a linear lamina traversing the area of attachment indi- 

 cates that it was separated into ligament proper and resilium. 



With these emendations of Gabb's descrii^tion it is evident that 

 Bemondia has all the essential features of the Crassatellida', or Crassa- 

 tellitida?, as the family is now called.^ The cardinal formula is the 

 same (|^^"), aud it differs from Crassatella {Crassatcllites) only in the 

 more equal development of the cardinal teeth, the partially external 

 position of the ligament, and the arrangement of the lateral laminie. 



Stearnsia is regarded as a synonym of Bemondia. The two species on 



iProc. Acad. Nat. Sci. Phila., 1887, p. 32. 



'^W. H. Dall, Tertiary Mollusks of Florida, Pt. ii, Trans. Wagner Free Inst, of 

 Sci., Ill, p. 539. 



