INDIANA PALEONTOLOGY. 64. 



by the tabula?, twenty millimeters in diameter. Number of lamelhe eighty-six, 

 in the circumference of a calix twenty-five millimeters in diameter, unequal in 

 size at the margin, abruptly sloping to the bottom of the calix, where the short 

 ones terminate, the longer ones continue, coalescing with the adjacent ones, 

 and abruptly end on reaching the center of the cup. Fossette consists of a very 

 slight depression on the anterior side of the tabula, but does not extend on the 

 aids of the calix. 



Found in the middle Devonian (upper Helderberg group) at the Falls of the 

 Ohio. Now in the collection of the author. 



PENTREMITES ALTUS, N. Sp. (Rowley.) 



Plate 23. Figs. 1, 2( ?)-3( ?). 



The basal region of this blastoid is quite convex and from the expanded 

 character of the body at the tips of the ambulacra, the cup formed by the basal 

 plates IS rather large. 



The radials are over half the length of tlie body, while interradials are 

 nearly a fourth. 



The ambulacra are about five-eighths the entire length of the body, moder- 

 ately broad and scarcely sunken below the radial lips. The four spiracles are 

 each doubled just within the external opening, by the sharp upper edge of the 

 interradial plate, the latter thus extending near to the central summit opening. 

 The anal opening is somewhat larger than a spiracle. A slight groove starts 

 from the lower point of the interradial and extends to tlie tip of the ambu- 

 lacrum, making with the lower interradial sutures an X in each interambulacral 

 area. This feature recalls a similar one on Lophoblastus. On the weathered 

 Dortion of the type, may be seen the outer side plates and pores, and below the 

 ambulacrum itself the tips of the hydrospires. 



This blastoid is much more contracted at the summit and expanded at the 

 ambulachral points than P. Pyriformis. The shape of the body outside of the 

 basal region is worn like, that of P. Conoideus. 



The description is made out from figure 1, a specimen obtained at New- 

 man's Ridge, East Tennessee. Fig. 2 is from near Bowling Green. Ky., and 

 is apparently of the same species, differing in one or two minor features. 



Both are from the Kaskaskia Group, and are in the collection of Mr. G. 

 K. Greene. 



