304 



Surface marked by numerous, very small and close set, radiating ribs. 

 Counting the smallest on each side, that can scarcely be seen without the 

 aid of a lens, there are about forty of these ribs on each valve. Hinge 

 dentition and muscular impressions unknown. 



Dimensions of the only specimen that the writer has seen : length, 

 inclusive of the beak, about nine millimetres ; maximum breadth, not 

 quite twelve mm.; greatest thickness, four mm. 



East end of Maud Island, C. F. Newcombe, 1895 : a well preserved 

 cast of the interior of both valves, with portions of the inner layer of the 

 test adherent thereto, but with a small piece of one side of the umbo and 

 beak of the ventral valve broken off. In general appearance this little 

 shell is not unlike a small and finely ribbed Orthis, but it may not be 

 quite full grown. It has almost the same marginal outline as the Tere- 

 hratella (Jalifornica of Stanton,* from the Knoxville beds of California, 

 but that species appears to be a true terebratuloid, with a minutely 

 punctate structure and the beak of the ventral " truncated by the large 

 round foramen." 



CCELENTERATA. 



AsTROC.ENiA IRREGULARIS, Whiteaves. 

 Astrocwnia irregularis, Whiteaves. 1884. This volume, part 3, p. 246, pi. 33, fig. 1. 



In 1897 Dr. Newcombe found a reef of this species about a quarter of 

 a mile from Gold Harbour Village, on the north shore of Maud Island, 

 and has since presented a small piece broken from it to the Museum of 

 the Survey. 



* Bulletin U. S. Geological Survey, No. 133, p. 33, pi. 1, figs. 12 and 13. 



