Talbot — New York Helderbergian Crinoids. 27 



At North Litchfield, this species was found associated with 

 Mariacrinus beecheri, Melocrinus pachy dactylics, Cordylo- 

 crinus phimosus, Thysanocriniis arborescens. Homocrinus 

 scoparius, Lepocrinites gebliardi, and Dalmanites sp. The 

 crowns are not numerous, but judging from the associated frag- 

 ments of stems this spot must have been very favorable to the 

 growth of Ifelocrinus nobilissimus. On one slab about four- 

 teen inches long (pi. II), four crowns were found with columns 

 belonging to forty-six more. The only other fossils on this slab 

 are one Conularia and two Bryozoan fragments. 



Horizon and locality. — Coeymans limestone at Litchfield 

 and North Litchfield. 



Cotypes in the American Museum of Natural History. 



Melocrinus pachydactylus (Conrad). Plate I, figure 1. 



Astrocrinites pachydactylus Conrad, Ann. Eept. Pal. N. Y., 1841, p. 34. — 

 Mather, Geol. Eept. N. Y., 1843. p. 347 ; text-fig. 6 on p. 345. 



Mariacrinus pachydactylus Hall, Nat. Hist. N. Y., Pal., vol. iii, 1859, p. 

 107, pi. 3, figs. 1-4. 



Mariacrinus paucidactylus Hall, ibid., p. 109, pi. 3, fig. 5. 



Melocrinus pachydactylus Wachsmuth and Springer, Eev. Palasocr. , Pt. II, 

 1881, p. 122; Proc. Phila. Acad. Nat. Sci., vol. xxxiii, 1882, p. 296; N. A. 

 Cri. Cam., vol. i, 1897, p. 296, pi. xxiii, figs. 4 and 5 ; pi. xxiv, figs. 4a and 

 4b. 



Melocrinus paucidactylus Wachsmuth and Springer, Eev. Palaeocr., Pt. II, 

 1881, p. 122; Proc. Phila. Acad. Nat. Sci., vol. xxxiii, 1882, p. 296; N. A. 

 Cri. Cam., vol. i, 1897, p. 296. 



Actinocrinus polydactylus Bonny, Schenectady Eeflector, 1835. 



Although this species heretofore has been considered a rare 

 fossil, it is now represented in the Yale University Museum by 

 thirteen specimens. Little additional knowledge of the calyx, 

 however, has been gained. In all cases where the distichals 

 can be distingushed from the other plates, their number is two, 

 instead of three. The former number agrees with all previous 

 figures ; yet, in their description, Wachsmuth and Springer 

 make the distichals three in number.* 



One of the rays, though incomplete, shows nineteen arms, 

 which are plainly seen to be uniserial, not biserial as previously 

 described and figured. f The actinal sideypf the rays and arms 

 shows the ambulacral groove. As to the number of brachials 

 iu the successive orders of the plates of the rays, careful exam- 

 ination of the specimens at Yale yields results different from 

 those reached by Wachsmuth and Springer 4 Brachials of 

 the fourth, fifth and sixth orders have seven plates, and the 

 subsequent orders seem to alternate with six and seven to the 



*N. Am. Cri. Cam., vol. i, p. 296, 1897. 



fXat. Hist. N. Y., Pal., vol. iii, 1859, p. 108, pi. 3, figs. 1-3 and 4a; N. 

 Am. Cri. Cam., Atlas, pi. xxiii, figs. 4 and 5 ; pi. xxiv, figs. 4a and 4b. 1897. 

 X Ibid., vol. i, p. 297. 



