﻿SCHUCH1 I | 



SILURIC AND DEVONIC CYSTIDEA 



235 



Pectinirhombs on plates 1 and 5, 12 and 18, about equally large 

 and having about 33 dichopores, while that on plates 14 and 15 is 

 largest and has 43. 



Madreporite prominent, situated as usual on plate 18; the hydro- 

 pore is very minute. 



Anal area as in P. clarki, prominent, consisting of 2 circles of 

 pieces, die miter one made up of 4 or 5 right posterior plates, 3 minute 

 pieces on the left, and plate 13. The inner pyramid is not preserved 

 in the specimen at hand. 



Comparisons. — This species is most closely related to P. elongatus, 

 but the greater size and elongated theca of the latter will readily dis- 

 tinguish it. P. clarki is similar, hut the greater size, oval outline, 

 and the differently sculptured plates will serve to identify it. 



Formation and locality. — The only specimen known was found by 

 Mr. Hartley at Devil's Backbone, opposite Corringansville, near 

 Cumberland, Maryland. The horizon is in the upper portion of the 

 Manlius or the lower half of zone "D. P>. Ba." of the section described 

 by the writer on p. 418, Proceedings of the U. S. National Museum, 

 1903. 



Cat. number 35,067, U. S. N. M. Presented by Mr. Robert H. 



Gordon. 



PSEUDOCRINITES ELONGATUS n. sp. 

 (Plate XXXV, figures 6, 7) 



Oral end of the only specimen broken away, but the length seems 

 to have been about 40 mm.; width 23 mm.; depth 17 mm. For 

 general form and shape of individual plates, see figures 6, 7, plate 

 xxxv, and text-fignre 31. 



Ambulacra prominent, extending around the entire periphery of 

 the theca and touching the column. As the top of the theca is broken 

 away, the exact number of q~ 



brachioles cannot be counted, __ f^Z^y,^ 



but. on the basis of brachioles 

 preserved and the close rela- 

 tionship to P. siibqiiadratus, 

 the total number on each side 

 of an ambulacrum is estimated 

 to be between 26 and 28. Am- 

 bnlacral groove large and deep ; 

 ambulacralia not preserved. 



Basal pectinirhomb has about 65 dichopores. that of plates 12 and 

 18 about 75, and of plates 14 and 15 about no. 



0£W, 



Fk 



31. — Analysis of Pscudocrinites 

 elongatus n. sp. 



