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26 EIGHTEENTH REPORT ON THE STATE CABINET. 



GENUS (iLYPTASTER (Hall). 

 GLYPTASTER OCCIDENTALIS. 



Glyptaster occidentalis : Hall, Transactions of the Albany Institute, Vol. v. 1863. 



The original specimens of this species were derived from the Niagara 

 shales and shaly limestones at Waldron, Indiana. Among the collections 

 from Racine, are some casts which are undistinguishable from those of 

 Waldron. and I have thus referred them. 



There are, however, some casts of a less rotund form, which is appa- 

 rently a distinct species. ^ •». V *- • XT^iA v-vx^^l^i^ A. . 



GLYPTASTER PENTANGULARIS (n. s.). 



Body reversed pyramidal, pentangular, regularly expanding to the bases 

 of the arms. Basal plates five, small ; subradial plates short, showing 

 the commencement of ridges which unite on the first radial plates. First 

 and second radials marked by a central longitudinal ridge, which divides 

 on the third radial plate, as in other species of the genus. Interradial 

 spaces quite flat. 



This species is much more slender in form than G. occidentalis . In its 

 casts which is the usual condition of the specimens, the smaller individuals 

 resemble the Stephanocrinus angulatus, with which it corresponds in size 

 and proportions. The larger specimens have a length of an inch and a half, 

 with a diameter of one inch at the summit. 



Formation and locality. In the limestone of the Niagara group at 

 Racine, Wisconsin. 



GENUS ACTINOCRINUS (Miller). 



Subgenus Saccocrinus (Hall). 



ACTINOCRINUS WHITFIELDI. 



Actinocrinus christyi : Hall, Descriptions of new species from the Niagara group. 

 Transactions of the Albany Institute, Vol v. 1863. 



Not Actinocrinus christyi : Shumard, Geol. Rep. of Missouri^ pa. 191, pi. A, f. 3. 1855. 



This fine species resembles the Actinocrinus {Saccocrinus) speciosus, 

 Hall ( Pal. N. Y. Vol. ii, pa. 205, pi. 46, f. 1) ; differing however in the 

 size and proportions of the plates, and the more prominent ridges upon the 

 plates of the radial series ; but principally difi'ering in having a second 

 bifurcation of the ray before the arms become free. 



This species from Waldron sometimes attains a length of nearly three 

 inches, and having a diameter at the summit of one and a half inches. 



Some specimens of casts from Wisconsin have the form and arrangement 



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