REPORT OF THE DIRECTOR I9IO I79 



irregularly punctate. Surface plain except for indistinct growth 

 marks. The length and width of the specimen as it lies on the slab 

 is 16.5 mm. The number of plications seems to vary. 



0^ 



■"■ e y china ? waageni nov. Two ventra and one dorsal valve, with enlargement of 



the surface. Oyster basin. Coffin I. 



Pedicle valve subovate in outline, longer than broad, convex, 

 widest somewhat in front of the middle. Beak rounded, apparently 

 incurved ; postlateral margins but slightly arcuate, passing into the 

 rather strongly rounded antelateral edges ; anterior somewhat pro- 

 duced, convex in outline. Little indication of shell having possessed 

 fold or sinus. Six plications occupy the anterior two-thirds of the 

 shell, the four lateral ones being rather indistinct and all of them 

 coarse and broadly rounded. Fine concentric lines mark the surface 

 of the shell together with broader concentric undulations. Interior 

 unknown. Shell symmetrically punctate as in Dielasma. 



Dimensions. Length, 15.5 mm; width, 13 mm. 



Remarks. This shell possesses the peculiar punctate character 

 of Dielasma, but in form it is similar to Hemiptychina or some 

 specimens of Notothyris described by Waagen. The punctations are 

 evidently coarser and more symmetrically arranged than in Waagen's 

 specimens of Hemiptychina, but the great disparity of the horizons 

 may account for this, especially if the genus sprang from Dielasma 

 or from the same radicle. The globular form of Dielasmina is not 

 suggested by our specimen. In this respect our specimen resembles 

 more closely Hemiptychina, especially H. sparsiplicata 

 Waagen. So long as its internal characters are unknown it may as 

 well rest in this genus as in any. I know of no American Missis- 

 sippian or Pennsylvanian species resembling it. 



Martinia glabra Martin 



Spirifera glabra Davidson. Quart. Journ. Gcol. Soc. Lond., XIX, 

 p. 170, pi. 9, fig. 9, 10; 1863. 



Spirifera glabra Dawson. Quoted by Dawson. Acadian Geol- 

 ogy, p. 291, fig. 89; 1868. 



Martinia glabra? Girty. U. S. G. S. Bull. 439; p. 70, pi. 9, 

 fig. 9^11. 



Specimens of this species arc common in the gray shales of Coffin 

 island, at Oyster basin. 



