﻿234 SMITHSONIAN MISCELLANEOUS COLLECTIONS [VOL. 47 



Basal pectinirhomb in the specimen of average size above men- 

 tioned, with about 42 dichopores, that of plates 12 and 18 with about 

 50, and that of plates 14 and 15, which is the largest, with about 68. 

 In the largest specimen there are as many as 120 in a rhomb. 



Hydropore minute and closely adjoining the rather large and 

 prominent madreporite, situated, as usual in Pscudocrinitcs, laterally 

 between the ambulacra on the edge of plate 23. 



Anal area well marked, consisting of 2 circles of plates. The outer 

 circle has 4 small plates in the right posterior corner, and these are 

 followed on the left by 3 very much smaller pieces. The latter are 

 not readily seen, and the first impression is that the 4 pieces of the 

 right posterior corner and plate 13 complete the circle. The promi- 

 nent anal pyramid has 7 triangular pieces. 



Column stout, composed of thick pieces near the theca. Length 

 unknown. 



Comparisons. — This species differs from other Pscudocrinitcs 

 having ambulacra extending to the column, in its regularly oval out- 

 line. P. subquadratus is a much smaller species, subquadrate in out- 

 line, and with different thecal sculpturing. P. clongatus is more 

 elongate subquadrate. 



Formation and locality. — Of this species the U. S. National Mu- 

 seum has eleven specimens, the Geological Survey of Maryland one, 

 Mr. Gordon two, and Mr. Hartley ten. All are from the quarries 

 near Keyser, West Virginia. It gives the writer pleasure to name 

 this species for Dr. William Bullock Clark, the distinguished geol- 

 ogist and paleontologist, and the director of the Maryland Geological 

 Survey. 



Cat. number 35,070, U. S. N. M. 



PSEUDOCRINITES SUBQUADRATUS n. sp. 

 (Plate XXXV, figures 4, 5) 



Length of the only known specimen 16 mm.; width 12 mm.; depth 

 9 mm. The base of the theca is comparatively large, indicating a 

 stout column ; the oral end is flattened. Between the two flattened 

 ends the theca is slightly convex, giving it the subquadrate outline 

 indicated by the specific name. The sculpturing of the thecal plates 

 is decidedly vermicular, and not radiate as in most other species. 



Ambulacra prominent, rounded on the top, extending to the 

 column, composed of 26 comparatively stout basement plates bearing 

 13 brachioles on one side of each ambulacrum. Brachioles short, 

 very sk-nder, about 5 mm. long, and having about 10 plates in each 

 column. Ambulacra] groove large. Ambulacralia not preserved. 



