CRINOIDEA OF THE WAVERLY GROUvP. 171 



and in the arms becoming angular on the back, the bif^urcating plates 

 being very tumid or nodose, and those of the upper part of the arms 

 more prominent or sub-spinous. Upper margins of the plates of the 

 body and ra5'-s deeply concave exteriorly. 



Surface apparently finely granulose. 



Column, near the body, of moderate size, round, and rapidly tapering 

 below, composed of thin plates. 



A moderately well-preserved specimen of this crinoid shows no essen- 

 tial or important difference from F. lohatus, of the Hamilton group of 

 New York, described in the Fifteenth Report on the State Cabinet, page 

 124. The divisions and subdivisions of the rays are precisely of the 

 same character, and in the same order. The rays are sub-angular, and 

 the third radial plate is more prominent than other parts of the ray, 

 though from its weathered condition it is not so prominent. 



In the specimen under consideration the plates of the ray are not quite 

 so deeply depressed in the middle as the original of F. lohatus, but this 

 difference may be in part due to the greater pressure which this one has 

 undergone. In the typical F. lohatus the interradial series consists of 

 several plates, while in this one the character of these areas can not be 

 determined. An examination of better specimens may prove the absence 

 of these plates in the form under consideration, which would entitle it 

 to a distinct specific rank ; but in the presence of similar interradial 

 areas we can see no reason for a specific separation of the specimens from 

 the two localities. 



The difference in geological position is greater than we know in any 

 other species of this family of fossils, the F. lohatus being from the upper 

 part of the Hamilton group. At the same time we know several species 

 of Lamellibranchiate fossils which extend from the Hamilton to the 

 Waverly group. 



Formation ami locality: In shales of the Waverly group, Richfield, Summit county, 

 Ohio. 



FORBESIOCRINUS IvELLOGGI. 

 Plate 12, fig. 1. 



Forhesiocrinus Kelloggi; 17th Rept. on N. Y. State Cab. of Nat. Hist., p. 56, 1864. Extr. 

 published November, 1803. 



Body and arms somewhat robust ; body short. Basal plates barely vis- 

 ible above the column ; sub-radial plates small and triangular. The 

 primary radial series consists of four plates in each ray, which diminish 



