24 



NEW YORK STATE MUSEUM 



In the upper Guelph of Shelby was collected a single specimen which 

 possesses a rapidly widening corallum, narrow, thin septa and a deep cup ; 

 on account of these characters, it has also been referred to Z a p h. 

 racinensis rather than to Zaph. turbinata. 



KNTKROLASMA Simpson, i goo 

 Enterolasma cf. caliculus Hall (sp.) 



Plate i, fig. i 



Streptelasma calicula Hall, Paleontology of New York. 1852. 2: in, pi. 32, 

 fig. xa-k 



Of somewhat more frequent occurrence than the foregoing in the Guelph 

 at Rochester are casts of a smaller turbinate, rapidly expanding zaphrentid, 

 slightly curved toward the apex. These in exterior appearance suggest 

 identity with Streptelasma caliculus Hall. Unfortunately in 

 nearly all specimens the internal structure has been destroyed by dolomitiza- 

 tion, but a single specimen has afforded in thin section, evidence of a pseudo- 

 lamella consisting of the involved vermiform projections of the septa sug- 

 gesting the convolutions of the intestines. Simpson * has united under 

 the generic name Enterolasma, species presenting this peculiar divergence 

 from the structure of Streptelasma, assuming the S. strictum Hall, of 

 the Helderbergian, as the type of the genus. Two other species of Niaga- 

 ran age have been referred by this author to the genus, viz P e t r a i a 

 waynensis Safford and Streptelasma radicans Hall, the former 

 from Perry county, Tenn., the latter from Waldron Ind. Enterolasma 

 waynense differs from E. caliculus in the coarser and more promi- 

 nent costae and the sharper concentric striae. It is also proportionally 

 more slender. These are but slight differences, which are not pronounced 

 in the Guelph species. Enterolasma radicans has a more irregular 

 growth and a broad base of attachment. 



This characteristic dwarfed coral has not been observed in either the 

 lower or upper Guelph beds at Oak Orchard creek, while it was found to be 



'N. Y. State Mus. Bui. 39. 1900. 



