316 PROCEEDINGS OP THE ACADEMY OP 



secondary radial, while the space above is occupied by several 

 much smaller pieces. 



Arms four to each ray, rounded on the dorsal sides, slender, of 

 moderate length, very gradually tapering, simple, and composed 

 of ver3'' short, slightly wedge-formed pieces, each of which bears 

 a pinnule at its larger inner lateral end; pinnules slender, rather 

 closely arranged, deeply furrowed on the inner side, and appa- 

 rently composed of rather long joints. 



Surface of body plates all ornamented with distinct radiating 

 costae, starting from the centre of each piece, and passing one to 

 each of its sides so as to connect with others on each contiguous 

 piece : of these costoe, those passing up the middle of each of the 

 radial series are a little larger and more prominent than those of 

 the interradial plates, while they bifurcate with the rays so as to 

 send a division up each of the secondary radial series, toward 

 the upper part of which they become more prominent and rounded, 

 beins; there of about the size of the free arms. Column unknown. 



Height of body, 0.60 inch; breadth, about 0.68 inch; length of 

 arms, 1.05 inch; thickness of same, 0.05 inch; number of joints, 

 in a space of 0.10 inch near the base, eight. 



This very beautiful species reminds one, by its sculpturing, of 

 the common typical species G. decadacti/Jus, from which, however, 

 it may be at once distinguished by its proportionally broader and 

 shorter body, with sides rounding regularly under to the column 

 instead of being obconical. It also has proportionally more 

 slender arms, and differs materially in having, in each secondary 

 radial series, from nine to eleven pieces between the first bifurcation 

 of each ray and the arm bases, instead of only two. In the form 

 of its body, it agrees more nearly with G. ornatus of Billings; but 

 it differs materially from tliat species in having twenty arms in- 

 stead of only ten, as well as in less important details. 



The specific name is given in honor of Mr. C. B. Dyer, of Cin- 

 cinnati, Ohio, to whom I am indebted for the use of the very fine 

 specimens from which the description was made out. 



Locality and position. — Cincinnati group of the Lower Silurian, 

 100 feet below tops of hills at Cincinnati, Ohio. 



GLYPTOCRINUS DYERI, var. SUBGLOBOSTJS, Meek. 



There is, in Mr. Dyer's collection, a specimen showing the whole 

 of the anal side of the body, all the way up, and more or less of 



[February 13, 



