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Family DICHOCRINIDJK. 



MCHOCRINUS BOZEMAXENSIS. 11. Sp. 



Plate Til, Fig, 4, azygous view of calyx and arms. 



Species medium size. Calyx obconoidal, nearly as high as wide. 

 Surface longitudinally lined or sculptured, but this feature is not 

 shown in the illustration, because the upper surface of the calyx is 

 worn and it would have to be supplied; some of the ornamentation 

 only, in the lower part of the specimen is preserved. Sutures not 

 impressed. Column small and round. 



The two basals form a little cup about twice as wide as high. It 

 is contracted above the bottom so as to leave an expanded basal rim. 

 The first radials are a little less than twice as long as wide and very 

 slowly increase in width to the superior end, which bears a concave 

 facet about one-half the width of the plate for the attachment of the 

 second radial or first brachial. Second radial short, rounded. Third 

 radial about the size of the second, pentagonal, axillary and supports 

 upon the upper sloping sides the free arms, The arms bifurcate on 

 the third plate, giving four arms to each ray. There are, therefore, 

 twenty arms in this species, provided only, that the ray opposite the 

 azygous plate, which cannot be seen in our specimen, is like the 

 others. The arms are long and composed of a single series of cunei- 

 form plates, each one of which bears a long, coarse pinnule. The 

 vault cannot be seen in our specimen. 



Found in the Upper Burlington or Lower Keokuk, on Bridger 

 Mountains, near Bozeman, Montana, by Earl Douglass, and now in 

 his collection. 



TALAROCRINUS PATEI, 11. Sp. 



Plate III, Fig. 9, view opposite the azygous side of a large speci- 

 men; Fig. 10, azygous si<h } of same; Fig. 11. azygous side 

 of a small specimen, plates of the vault, though 

 preserved, are no! indicated; Fig. 12, 

 opposite view of same. 



We have ten specimens belonging to this species, the smallest of 

 which is not half as large as the smaller one illustrated; the larger 

 one illustrated is the largest in the collection. 



General form of the calyx and vault, somewhat obovate. Calyx 

 broadly truncated and somewhat in the form of the frustum of a cone. 



