Talbot — New Yorh Helderbergian Crinoids. 25 



This species is associated with Melocrinus nobilissimus, M. 

 pachydactylus, Mariacrinus beecheri, and Cordylocrinus plu- 



7)10SUS. 



Horizon and locality. — Upper third of the Coeymans lime- 

 stone at North Litchfield. 



Holotype in the Yale University Museum. 



Family, Melocrinidce Roemer. 

 Subfamily, Melocrininw. 



Genus, Mariacrinus Hall. 



In re-diagnosing the genera Mariacrinus and Melocrinus, 

 "Wachsmuth and Springer recognized the fact that the arms of 

 the former remain apart and do not form the tubular append- 

 age which is so conspicuous in Melocrinus. The only species 

 in the Yale collection that shows this characteristic of Maria- 

 crinus is a new species, M. beecheri, in which the proximal end 

 of the ray forms a tube while the distal end is divided, the 

 arms diverging conspicuously. The species is thus seen to 

 hold a position intermediate between Mariacrinus and Melo- 

 crinus. As the features of the former are more strongly 

 developed, this species is referred to that genus. 



Genotype, M. plumosus Hall. 



Mariacrinus beecheri n. sp. Plate I, figure 3 ; text-figure 2. 



This species bears a resemblance to Melocrinus nobilissimus 

 but differs from it in features other than the division of the 

 rays. The auxiliary arm, instead of being comparatively incon- 

 spicuous, as in Melocrinus, is strong and prominent and lies 

 alongside the tube. 



The joints of the rays are longer than those 

 of M. nobilissimus, so that, although the arms /X}\ 



are given off more frequently than in the last y 



named species, they seem to take origin at 

 greater intervals. As in M. nobilissimus, the 

 stem joints alternate in 'size, but they are so 

 very thin in all parts of the stem, and especially 

 so near the crown, that there is no difficulty in 

 determining this form by the column alone. 

 The column is also much larger in proportion 

 to the size of the calyx. 



Specific description. — Calyx small, elongate, Text-figure 2.— 

 once and a half as long as wide, the increase in ^},T\°\^i e lT- 



.,,,. o? crmus beecheri 



width being very gradual. .Basals wider than w ith «, b and c as 

 long, pentagonal, not forming a projecting the last of the anal 

 cup, but continuing the width of the column. ^ nes of pl x at 4? m 

 Radials five, four heptagonal and one hexag- 

 onal. Costals two, the first hexagonal, more than half as large 

 as the radials, and the second smaller, pentagonal, and support- 



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