148 



Cincinnati Society of Natural History. 



minates in an acute point about two-sevenths of the entire 

 length of the shell from the anterior end. A sulcus arises on 

 the umbo of each valve and extends, gradually widening, to 

 the postero-basal margin of the shell, where it appears as a 

 projection, beyond what would otherwise be the termination 

 of the basal margiji and posterior slope. A shallower and 

 less defined sulcus occurs anterior to the above on the lower 

 half of the shell, but does not interfere with the basal margin. 

 Posterior to the sharp, angular, umbonal ridges that extend 

 from the beak to the end of the projection at the postero basal 

 margin, there is a wing-like extension formed by the prolon- 

 gation of the cardinal line beyond the postero-basal part of 

 the shell, and having a straight posterior end directed back- 

 ward to the lower extension of the angular umbonal ridges. 

 The superior point of this wing is broken off from our speci- 

 men, but, apparently, it did not extend above the cardinal 

 line. Surface of the shell anterior to the angular umbonal 

 ridge marked by exceedingly fine, close, lamellose lines of 

 growth. Wing apparently smooth. 



This species is distinguished from T. faberi by the com- 

 paratively narrower and more cylindrical form of the shell, 

 by the less arcuate form of the wing-like extension, less 

 defined and shorter anterior sulcus, and much smaller size. 



Found by S. A. Miller in the lower part of the Hudson 

 River Group, at Cincinnati, and now in his collection. 



Tellinomya Hall. 



It is a matter to be regretted that a generic name so well 

 established and defined as Tellinomya should be erroneously 

 attacked, and an attempt made to supplant it with a later and 

 less pleasing word, in any publication bearing the coat-of-arms 

 of any State. We are led to this observation by a recent 

 publication of the Geological Survey of. Minnesota, wherein 

 an attempt is made to substitute Ctenodonta for Tellinomya . 

 It is admitted that Tellinomya was defined and illustrated by 

 Hall several years before the word Ctejiodonta was applied to 

 the same genus of shells, but it is erroneously stated that 

 Tellinomya was preoccupied, and for that reason can not stand. 



