Agelacrinidae and Lepadocystinae 
469 
that these were correspondingly stout. The ornamentation is 
entirely different, consisting of an irregular network of interlacing 
raised lines. 
Genotype, Apiocystites tecumsethi, Billings 
Genus named in honor of the distinguished head of the Geolog- 
ical Survey of Canada, Dr. R. W. Brock. 
44. Brockocystis tecumsethi, Billings 
(Plate V, Figs. 2 A, B, C) 
Apiocystites? Tecumseth, Billings. Catalogues of the Silurian fossils of the 
Island of Anticosti, ivith descriptions of some neiv genera and species. Geolog- 
ical Survey of Canada. Montreal, p. 91. 1886. 
The original description of this species follows : 
This species is proposed for a Cystidean collected by Prof. R. Bell and 
H. C. Vennor, on Manitoulin Island in 1865. Only detached plates and 
fragments of the column were found. Most of the plates have a large 
hemispherical protuberance which occupies all of the plate, except a 
narrow flat border all around. The rhombs consist of two separated 
triangular spaces, their bases separated as in A. elegans, Hall. The 
column has from three to four lines in length at the point of attachment, 
encased in an ovoid mass which is either a secretion of the column 
itself, or a parasitic zoophyte, or, perhaps, a sponge. The surface of 
this part, as well as that of the tumid part of the plates, is covered with 
small polygonal pits. Near South Bay, Manitoulin Island; Prof. R. 
Bell, H. G. Vennor. 
The detached plates of the type series were shown me in 1904 
by Mr. Whiteaves. Similar plates are very common not only on 
the surface of the high hill southwest of Manitouaning but also 
along the road between Gore Bay and Kagawong, at a crossing 
over a wet weather stream, exposing a rocky bottom, about half 
a mile east of Ice Lake. As remarked by Schuchert {On Siluric 
and Devonic Cystidea and Camarocrinus, 1904, p. 212): ^^Until the 
theca of A.(?) tecumseth is known, this can not be regarded as an 
established species.’’ Fortunately, an excellently preserved 
specimen was found by the writer near the top of the Cataract 
limestone at the locality east of Ice Lake. It forms No. 8447 in 
the collections, of the Canadian Geological Survey, in the Victoria 
