﻿212 SMITHSONIAN MISCELLANEOUS COLLECTIONS [VOL. 47 



The columns are top-shaped bodies from 5 to 8 mm. long, with 

 a large, round, central canal. The segmented central portion of the 

 column is about 3 mm. in thickness, outside of which is a secondary 

 non-segmented deposit, as in Lepocrinites, giving the stem a total 

 diameter varying between 5 and 7 mm. The secondary deposit is 

 ornamented with small, polygonal, shallow depressions arranged in 

 circles. 



Until the theca of A. ( ?) tecumseth is known, this can not be re- 

 garded as an established species. 



Apiocystites( ?) huronensis Billings. Through the courtesy of 

 Professor Whiteaves the writer was allowed to study the holotype of 

 this species. It certainly is not a form of Apiocystitcs, and probably 

 represents a new genus, since the pectinirhomb of 12 and 18 rests 

 directly on that of plates 1 and 5. In other words, plate 12 rests on 

 plates 5 and 9 — an anomalous position for the former plate, and one 

 unknown in other American Siluric cystids. Billings's figure 28 is 

 inverted in the text, with the column uppermost. This illustration 

 shows all that is preserved in the holotype. The plates present are 

 4 and 1 of the first circle, 5 and 9 of the second, 12 of the third, and 

 part of 18 of the fourth circle. 



APIOCYSTITES ELEGANS Hall 



(Plate XXXIV, figures 4, 5) 



Apiocystitcs clcgans Hall, Nat. Hist. N. Y., Pal., 11, 1852, p. 243, pi. 51, 

 figs. 1— 17. 



To Hall's description (based on Lockport specimens) may be added 

 the following details seen in a very fine specimen in the collection of 

 Dr. B. E. Walker, Toronto, Ontario. It was found by Mr. J. Pettit 

 in the Rochester shales at Grimsby, south of Hamilton, Ontario. 



Length of theca 17 mm.; diameter about 13 mm. The specimen 

 is somewhat distorted, so that the actual diameter is not determinable. 



Ambulacra extending almost to the column, the pair, one on each 

 side of the anus, slightly converging, as does also the opposite pair. 

 Brachioles widely separated, from 1 1 to 12 on each side of an ambula- 

 crum. Ambulacralia extremely small, about 12 to each ambula- 

 cra 1. 



Pectinirhombs equal in size, each with about 10 dichopores. Those 

 on plates 5, 12, and 14 with strongly elevated rims, while those on 

 plates 4, 15, and 18 are almost without elevated margins. 



Anal pyramid not seen, but probably composed of 5 or 6 pieces. 

 It is surrounded by a prominent ring of 8 pieces set between plates 

 7, 8, and 13. 



