﻿NEW AND OLD MIDDLE DEVONIC CRINOIDS 



6i 





° 

 i<3 



The arrangement of the plates of the calyx is shown by fig. 2; and 

 fig. } shows the normal arrangement of plates in the anterior and 

 upper portion of the calyx. It will be seen that this form differs 

 from most speciesof Megis- 

 tocrinus in including the 

 lower plates of the biserial 

 arms in the upper portion 

 of the cup. As shown in the 

 diagram (fig. 2) the type 

 specimen appears to have 

 hut one costal in the left 

 postero-lateral ray, but the 

 specimen is broken, and this p IG . 2 . — Megistocrinus sphceralis n. sp. An 

 point cannot be determined incomplete individual, the holotype. 



with certainty. 



Tegmen elevated, regularly dome-shaped, its plates small, smooth, 

 or rarely spinose. The radial dome plates bear large spines. Anal 

 tube slightly eccentric. 



Column circular ; canal large, and obscurely pentalobate. 



° 3 ° 



'&&& 



"^oy 



o 



o 



o 



3 



% 



p IG _ 3 , — Megistocrinus sphtzralis n. sp. Plates of the specimen 

 represented by fig. la, pi. XV. 



Remarks. — This species somewhat resembles Megistocrinus no- 

 dosus (Barris), but differs from it in the presence of spines on the 

 higher plates of the calyx, and in the form of the tegmen which is 



