1887.] NATURAL SCIKNCES OF PHILADELPHIA. 85 



0. conicus, 0. fusiforviis, an undescribed Mesoblastus from New 

 Mexico to say nothing of Elaeacrinus from various localities, and 

 of three different species all having the central opening per- 

 fectly closed by plates, he would come to a different conclusion. 

 We have found Schizoblastus Sayi in especially good preservation, 

 with summit plates firmly attached and unincumbered by deposition 

 of fragments of any kind. It is by no means rare to find specimens 

 of this species, in which the summit plates and portions of the cov- 

 ering pieces are in place. They may be seen in several collections 

 in Bui'lington, and these parts may be vigorously brushed with the 

 stifiest bristles with entire safety. The same may be said of all the 

 above named species, and there can be no sort of question that a 

 plated covering does actually exist in all of them. 



With regard to the type specimen of Pentremites conoideus, how- 

 ever, we are fully convinced that Hambach is right, and that his 

 definition of the so called plates described and figured by Shumard 

 as covering the center and ovarial openings, as "ovulum-like bodies," 

 for which he was somewhat sharply ridiculed by Dr Carpenter ^ is a 

 perfectly correct statement. The species occurs abundantly at 

 Spurgen Hill, lud. in a friable, light-colored oolitic limestone, which 

 is composed almost entirely of minute organisms, small bivalves, 

 Gasteropods, etc., and these are interspersed profusely with small 

 egg-shaped bodies of almost uniform size. Nearly every specimen 

 of Pentremites from that locality has some of these bodies exposed 

 at the openings, but we find nowhere any regularity in their arrange- 

 ment, and they are seen equally plain in much worn and weathered 

 specimens. 



Promj^ted by a strong desire to examine Shumard's type, the speci- 

 men from which his figui*e was made, we applied to Dr. Hambach 

 for the loan of it from the Museum of the Washington University 

 at St. Louis, and he forwarded it to us with a promptitude and court- 

 esy, for which he has our warmest thanks. The specimen is very 

 interesting, and shows clearly that Shumard's figure is a fiction 

 The center appears to be closed, and also the spiracles, not by plates, 

 but by foreign particles such as we have described above. The 

 specimen has the appearance of considerable weathering ; none of 

 the outlines are sharp, and the spiracles, which in good specimens 

 are markedly angular, are here almost round. In one of the spira- 

 cles only, the arrangement of the particles appears somewhat like 



Ann. and Mag. Nat. Hist., Ser. 5, Vol. VI T I., 1881, p. 422. 



