96. CONTRIBUTION TO 



The radial plates are but slightly lobed above, and the Interradials can not be 

 made out as the summit of each of the three specimens before me is injured or 

 poorly preserved. The ambulacra are narrow and but little elevated. 



It is almost certain that these fossils are not Codaster atteniiatus nor C. 

 pyraniidatus, but until the hydrospire slits can be seen there is no abso- 

 lute certainty that they are even Cadasters. 



Upper Devonian, Charlestown, Ind. Collection of G. K. Greene. 



METABLASTUS BIPYRAMIDALIS?, Hall, Rowley. 



Plate 30. Figs. 28, 29, 30-31. 



The basal plates form a low, but strongly triangular pyramid. The radial 

 plates are long and with a strong central ridge from the distal ends of the am- 

 bulacra to the basal plates. 



The interradial plates are found at the extreme upper ends of the interam- 

 bulaeral areas and only visible on a side view in the top of the excavated 

 grooves. The interambulacral areas slope toward the summit from the lower 

 ends of the ambulacra, and thus form the second pyramid, as implied in the 

 name. The ambulacra are elongate, narrow and about two-fifths of the body 

 lengtli ; deeply sunken in the radial sinuses, especially at the summit. 



The anal opening perforates the end of one of the interambulacral areas, 

 but no spiracles are visible on the specimen before us. 



The surface ornamentation is not preserved. 



In the center of the triangular excavation at the base is the small colum- 

 nar facet. 



This fossil comes from the Warsaw beds at Lanesville, Ind., and the fig- 

 ured specimen is the property of Mr. G. K. Greene. 



ORBITREMITES GRANDIS, N. Sp., (Rowley.) 



Plate 30. Figs. 34-35. 



The specimen from which this description is made out is a natural cast of 

 the visceral cavity and nothing but the great size of the specimen and its 

 unique plate arrangement could induce us to describe a species from such ma- 

 terial. The fossil is a giant of its kind, subglobose with a very large and 

 probably somewhat concave base. 



The radials are but little more than half the length of the body, while 

 the interradials are a little less than half the entire body length. The 

 ambulacra, from very narrow at their distal ends, increase in width upward 

 toward the summit. They were probably a little sunken below, but above the 

 surface outline above. 



