Remarks upon the Kaskaskia Group. 39 



two which join the azygos plates. The posterior second radial bears 

 upon each of its superior sloping sides an arm, while each of the other 

 four second radials bears on one superior sloping side an arm, atid 

 upon the other a third radial bearing two arms; thus furnishing to the 

 crinoid fourteen arms. 



Third radials. — The four third radial pieces are each pentagonal, 

 and nearly twice as wide as high. 



Azi/yos interradials. — There are three azj'gos interradials visible 

 upon the outer side, the third one of these is seen as high as the first 

 arm pieces, and thus indicates that it may unite with other plates 

 which terminate in a pointed proboscis within. The first or lower az}'- 

 gos interradial rests an ai-cuate side upon a sub-radial, joins its left 

 arcuate side with a first and second radial, and its left side with the 

 second and third azygos plates. The second azygos plate is very irreg- 

 ularlj"^ pentagonal. The lower side rests upon a sub-radial, the left in- 

 ferior side joins the fii'st azygos plate, the right inferior side joins the 

 first radial, the right superior side joins a second radial, while the left 

 superior or upper side supports the third azygos plate. 



Proboscis. — The proboscis is seen projecting like a needle at the 

 upper broken end of the specimen which is illustrated. The azygos 

 interradials cover a convex ridge over the vault, which terminates at 

 the center in a small proboscis. 



Arms. — The arms are strong, simple, convex on the outer side, and 

 flattened laterall}^ so as to fit close together. The first arm plate is 

 double the size of the succeeding ones, the next two to four arm plates 

 are wedge shaped, and above these there is a double alternating series 

 of wedge-shaped pieces in each arm. The number of single wedge- 

 shaped pieces, between the first arm plate and the double alternating 

 .series, A'aries in different arms in the same specimen, and probably 

 varies in difi'erent specimens. The furrow upon the inner side of each 

 arm is protected b}" a pinnule springing from ever}- plate, upon each 

 side of the arm; this arrangement, when the arms are folded, fills the 

 interior with a dense mass of pinnules. 



This species is readil}' distinguished from Eupachycrinus boydi by 

 the number, position and shape of the azygos interradials, as well as 

 by the form and proportional size of other plates. 



Locality. — This species is described from specimens in the collection 

 of Prof. A. G. Wetherby, who discovered them in rocks of the age of 

 the Kaskaskia Group, in Pulaski count3% Kentucky-. 



