280 Crania reticularis. 



Crania reticularis — (S. A. Miller). 



Shell small, subelliptical in outline with a straight cardinal margin, 

 or sometimes more nearly circular in outline. Dorsal valve moderate- 

 ly prominent; apex prominent, acute and situated close to the 

 cardinal margin, in fact, it seems by its abrupt termination, to form 

 part of this margin. 



Fig. 22. Crania reticularis. Magnified 3 diameters. 



Surface marked by punctures, arranged, as shown by the figure, in 

 a pecidiarly beautiful manner. The rows of punctures, from the car- 

 dinal margin, on each side the apex, curve downwards a little, as they 

 ascend toward the apex. The rows as they leave the lateral margins 

 form the same curves, so that the rows soon cross each other, giving 

 the punctures the rhomboidal form, and the surface the checkered 

 appearance, formed by curved lines gradually approaching and crossing 

 oach other, like "engine turnings" on a watch-case. 



Length of a specimen 0.08 inch; width 0.11 inch; convexity 0.04 

 inch. 



The specimen figured is one of a number found, attached by the 

 lower or ventral valve to the under side of a worn piece of Tetradium 

 fibrattim, near Brookville, Indiana, by Mr. Ed. R. Quick, a collector of 

 that place. The specimens vary in form considerably, but the punc- 

 tate surface is as distinct and uniform as it is in Trematis miUepunctata. 

 The shell has the same appearance, that the shells have in the latter 

 genus, and it may be, that it is a true Trematis. 



The acute apex and the variability of form, however, have induced 

 me, at present, to class it Avith the Crania. The lower valve and in- 

 terior are unknown. 



Some further remarks upon the genus Anomalodonta. 

 By S. a. Miller. 



Prof. C. A. White takes occasion, once in a while, to ci'itieise the 

 the genus Anomalodonta. This he has a perfect right to do, in his own 

 way, and if he showed an ordinary respect for truth and fairness, 1 

 would enjoy his criticisms, and be only too glad to republish them. 

 Indeed, no man has any right to object to a truthful criticism of his 



