Oct., 1907. New Crinoids — Slocom. 297 



a row of three or more plates, gradually diminishing in size; these 

 anal plates are similar, in size to the corresponding radial, costal and 

 distichal plates; on either side of the anal plates is a series of plates 

 similar to, but slightly smaller than, those of the interbrachial areas, 

 with the exception that there are three in the third row instead 

 of two. 



This species somewhat resembles H. benedicti S. A. M. in general 

 appearance, but it is distinguished from that species by having a more 

 shallow and expanded basal cup. The diameter of the calyx is greater 

 in proportion to its height in H. farringtoni than in H. benedicti, and 

 both the constriction below the arm bases and the second and third 

 distichals are wanting in H. farringtoni. In the form of the calyx 

 and the ornamentation of the plates H. farringtoni resembles H. lemon- 

 tensis, but they are distinguished by the shape of their first costals 

 and by the number and shape of the plates in the interbrachial areas. 



The type specimen of H. farringtoni, on which this description is 

 based, consists of a natural cast of the dorsal cup accompanied by a 

 portion of the natural mold. The sutures are well defined on both 

 cast and mold. The mold comprises two rays, one interbrachial 

 area and more than half the anal interradius. An impression taken 

 from this mold gives the external form of the calyx and the surface 

 markings of the plates. As the basal plates are missing from this mold, 

 the impression of a mold in the collection of the University of Chicago 

 is also figured, Plate LXXXVII, Figs. 1 and 2. The type is somewhat 

 crushed, thus giving a wider appearance in proportion to its height 

 than is natural. 



The specific name is proposed in honor of Dr. O. C. Farrington, 

 Curator of the Department of Geology of the Museum. 



Locality : This species is represented in the Museum collections by 

 the type specimen P 8474, and a natural cast, P 8949. These were 

 collected by the writer in the Niagaran limestone of the spoil heaps 

 along the Chicago Drainage Canal about a mile east of Lemont, Illinois, 

 one in the fall of 1905 and one in the spring of 1906. The specimen 

 in the collection of the University of Chicago is from the same 

 locality. 



Habrocrinus lemontensis sp. nov. Plate LXXXVII, Figs-. 8-10. 

 The calyx is urn-shaped with an expanded hexagonal base ; mod- 

 erately constricted between the prominent arm bases, giving a pentag- 

 onal section to the dorsal cup. The dome is not preserved. The 

 plates of the dorsal cup are thick and depressed with nodes near the 

 angles of the plates. The sutures are situated in deep furrows formed 



