Description of Some Cincinnati Fossils. 



147 



to the postero-basal extremity. Anterior end contracted for- 

 ward of the beaks, subacutely pointed and then broadly 

 rounded into the basal margin. Body of each valve marked 

 by a shallow and ill-defined sinus that is directed downward 

 and backward from the umbo, and gradually widens to the 

 basal margin, which it slightly contracts in the middle part. 

 Posterior umbonal ridge low, subangular, but becoming more 

 rounded, and less defined toward the postero-basal end of the 

 shell. Antero-umbonal ridge rounded and indistinctly defined. 

 Surface of the valves marked by concentric lines of growth, 

 and also by strong undulations from the subangular part of 

 the posterior umbonal ridge to the front, the undulations 

 being deepest at the anterior end of the shell. There are 

 also well-defined radiating lines on the posterior umbonal 

 ridge, and the whole surface is covered with pustules that 

 suggest the probability that they indicate the presence of 

 spines, as in Orthodcsma byrnesi. The shell was preserved in 

 Orthodesma byrnesi and also the matrix, in which the speci- 

 men was embedded, and the spines were well preserved, though 

 so fine that it required a magnifier for their examination. 

 They reminded one of the spines on some species of Prodnctns. 

 This species is founded on numerous casts, but no part of 

 the shell is preserved. There was no gaping of the shell at 

 either end. 



Found in the lower part of the Hudson River Group, at 

 Cincinnati and Covington, and now in the collection of Mr. 

 Faber. The specific name is in honor of Mr. George Ashman, 

 a well-known Cincinnati collector. 



•Technophorus cincinnatiensis n. sp. 



Plate 8, Fig. 75, left valve, magnified four diameters; Fig. 16, 

 same, natural size. 



• 



Shell very small, somewhat trapezoidal in outline, a little 

 more than twice as long as wide, and a little wider than thick. 

 Cardinal lines straight, anterior end almost regularly rounded 

 into the basal margin, which is almost parallel with the car- 

 dinal line. Beak extends beyond the cardinal line and ter- 



