20 Talbot — New York Uelderbergian Crinoids. 



of the specimens of Ilomocrinus are in almost perfect condi- 

 tion, and where the fine cirri are visible on the stem the grace 

 and delicacy of this species are well shown (pi. Ill, ftg. 3). 



The following additions are made to Hall's description : — 



Yentral sac strong, elongated, sometimes three-fourths as 

 long as the arms, the upper part composed of vertical rows of 

 small hexagonal plates. The upper end of the sac probably 

 has five large plates, which are drawn out into spines, some- 

 thing like those in Scapliiocrinus unicus. Three of these 

 spines and traces of a fourth can be seen in one specimen, and 

 their position shows that a fifth was probably present origi- 

 nally. These spines are not scattered irregularly over the 

 upper surface, as is indicated in Hall's figure. Column long 

 and slender, consisting of irregularly alternating larger and 

 smaller joints, round below and becoming obtusely angular and 

 enlarged above. Canal small and round. Shortest column 

 observed 4 cm in length ; longest, which is still incomplete, 15 cm 

 long. Very delicate cirri are preserved, but in no specimen 

 are they found above the middle of the stem. Wherever the 

 distal end of the column is present, there is a coil or loop, as if 

 the stem twined around some support (pi. Ill, fig. 3). No 

 indications of the clustering of columns mentioned by Hall 

 were seen in the Yale collection. 



Horizon and locality. — Common in the thinly laminated or 

 shaly layers of the Coejmians or Lower Pentamerus, at Scho- 

 harie, Jerusalem Hill and North Litchfield. Hall reports the 

 species from the Manlius, or Tentaculite, limestone,* but no 

 such specimens have come under the writer's observation. 



Cotyjpes (used by Wachsmuth and Springer for the revised 

 genus) in the American Museum of Natural History, from 

 Litchfield, N. Y. 



Family, JEdriocrinidce n. fam. 



In the specimens of Edviocrinus under observation, there 

 are differences that at first seemed to have specific, if not 

 generic value. There are two quite common forms — -one (No. 

 1 and No. 2)f the small hemispherical cups, so well known to 

 collectors in the Helderberg Mountains ; and another (No. 3) 

 like the preceding only that the cup has a prominent band or 

 ring around the upper margin. There are other forms that 

 are not so common, however ; and they can be divided into 

 two groups, or even three. One specimen (No. 4) about twice 

 as high as the common ones has the hemispherical cup, above 

 which and fused to which is a solid band ; and above this still 

 another band of six fused plates, twice as high as the lower 



*Nat. Hist. N. Y., Pal., vol. iii, p. 103, 1859. 

 f Numbers refer to those on pi. IV, figs. 1-6. 



