232 The Ottawa Naturalist. [March 



ON AN OCCURRENCE OF HYBOCYSTIS IN ONTARIO. 



(Plate II, Figures 1-5) 



By W. a. Parks, Ph.D., Associate Professor op Geology, 



University of Toronto. 



In the Journal of the Cincinnati Society of Natural History 

 for 1880, Professor Wetherby records the discovery of seven 

 specimens of a remarkable organism which he describes as 

 Hyhocystites prohIcmaticus,veievv\ng the genus to the Cystoidea, 

 as the name implies. The same specimens were examined by 

 Herbert Carpenter who decided that their relationships were 

 with the Blastoids rather than with the Cystids.* Wachsmuth 

 and Springer in their revision of the Palaeocrinoidea, are of 

 the opinion that these forms are really Crinoids of low organiza- 

 tion. In view of the diverse opinions as to the proper place in 

 a classification of this remarkable genus, it will be of interest 

 to students of the Echinodermata to learn of its occurrence 

 in a new locality ^the first since the original discovery in 

 Mercer County, Kentucky. The Trent Valley Canal cutting 

 in Eldon tp., Victoria County, near Kirkfield, Ont., has yielded 

 the University collector, Mr. Joseph Townsend, a fine series 

 of Crinoids, Cystids and Asteroids. In working over this 

 material one excellent specimen of H. prohlematictis and three 

 of a new species of the same genus were found. As the present 

 example of Wetherby's species is in a much better state of 

 preservation than any of the original forms it is hoped that 

 a few additional notes on the anatomy of this interesting 

 fossil will not be superfluous. Rather than to enter the dis- 

 cussion as to the affinity of the organism the writer prefers 

 to accept Wachsmuth and Springer's conclusion and to regard 

 it as a Crinoid. The almost exact resemblance to Hyhocrinus 

 in the arrangement of the calyx plates and in the character of 

 the anal orifice tend to strengthen the decision of these authors. 

 An emended description of Hyhocysiis prohlematicus follows: 



Basals. ^Five, pentagonal, the two posterior plates symmet- 

 rical and larger than the other three. This forces the column 

 into an excentric position. (Fig. 5). 



Radials. The second ring of plates consists of four 

 radials and a posterior hexagonal anal (azygous plate). This 

 plate bears on its upper left side a small upper azygous or 



* Quarterly Journal, Geo]. Soc, London, p. 307, pi. XL, 18S2. 



