472 PALjEONTOLOGUGAL report of geological survey.. 



first radial, Column cylindrical, formed of pieces of equal thiekness, 

 articulating by radiated surfaces, the rays covering the entire surface ; . 

 perforated ; opening small ; pentelobate ; side arms at irregular inter- 

 vals, frequently opposite each other, formed of similar piecesto the 

 column. 



This species differs from all others heretofore described, being much 

 larger; the whole character is coarse and strong ; the pieces are re- 

 markably thick — in the young, of a similar sized specimen, being 

 twice the thickness of any known species. The general form is near- 

 est that of P. floreales. Say. 



Length of specimen under description, - - 2. 1 ^ 5 - 5 - inches. 



Breadth of specimen under description, - ~- ^.-j^ inches. 



Vertical circumference, .... Q-y^\ inches. 



Transverse circumference, .... 6.^7 inches. 



In the largest specimen observed, the pseudambulacral field is l. T Vo 

 inches; that of our specimen is l. T Vo inches; length of smallest spe- 

 cimen, one inch; the field of this specimen is yi^, (half an inch.) 



The pieces forming the pseudambulacral areas, are thiner than those 

 of the glolosus or pyriformis, (small species.) 



GENUS ASTEROCRINUS. Lyon. 



Gen. char. — Column, cylindrical, perforated; base, bilobate; prima- 

 ry radialsfive; secondary radials, first series, ten; second series, twen- 

 ty; lobe pieces, five; arms twenty,, formed of a double row of joints. 



ASTEROCRINUS CAPITALIS. Lyon. 

 (Plate III. fig. 1, 1 a, 1 b, 1 c, 1 d, 1 e, If, l g , lh.li, Ik.) 



Specific description. — Body, viewed from above, presents somewhat 

 the form of an irregular five-pointed star*; viewed in profile, erect it 

 has much the form of a Corinthian capital, slightly contracted near its 

 base. 



Column, cylindrical, composed of numerous, unequal-sized, thin, cir- 

 cular pieces. The articulating facets are striated around their mar- 

 gins—the eleva^d ridges of one joint fitting into corresponding 

 depressions in those which adjoin it. At a short distance from the body 

 these pieces are arranged into the column in sets of three, between two 



•The spee'mec figured, is slightly crushed, therefore the star-like figure is not so remarkable. 



