TRENTON CONGLOMERATE OF RYSE5DORPH HILL 85 



exists a great similarity between the habitus of this and M. 

 u 1 r i c h i , which finds its expression in the slightly convex dor- 

 sal line, well rounded anterior and posterior sides, scattered pits 

 on the surface border, and the obscurely crenulated margin, 

 which is also indicated in some of the species from Rysedorph 

 hill by a faint radiation and radial arrangement of shallow 

 impressions on the border. On the other hand, the Quebec form 

 is relatively longer, has its greatest convexity posteriorly instead 

 of centrally, and lacks the central smooth space. Prof. Jones 

 had apparently only a single valve for description, and the pos- 

 sibility is therefore not excluded, that more extensive material 

 would have presented features more closely agreeing with M. 



u 1 r i c h i. 



Macronotella fragaria sp. nov. 



PL 6, fig. 3-5 



Another valve of Macronotella was found in the same lime- 

 stone, possessing different characters from the foregoing. 



Diagnosis. Carapace elongate, semiovate; cardinal margin 

 nearly straight, anterior and posterior cardinal angles very ob- 

 tusely rounded; anterior and posterior margins boldly rounded, 

 ventral margin less curved. Surface strongly convex, culminat- 

 ing a little ventrally and posteriorly (?) of the center, very 

 coarsely punctate; in the center is a circular, slightly projecting, 

 smooth, flat plate, from which a tapering ridge extends to near 

 the cardinal line. No border observable. 



Dimensions. Length, 1.7 mm; hight, 1.5 mm; thickness, .6 mm. 



Horizon and locality. In the gray crystalline limestone pebbles 

 of the Rysedorph hill conglomerate. (Croup 7) 



Observations. This form differs markedly from both the other 

 species by its strongly rounded cardinal angles, the culmination 

 of the valve ventrally and posteriorly from the center, the 

 absence of the border and the presence of the tapering ridge. 

 The absence of the dorso-central inflation and of the border 

 removes this form so much from the typical expression of the 

 genus that the propriety of referring thereto may be ques- 



