THE OTTAWA NATURALIST 



VOL. XXIII. OTTAWA, DECEMBER, 1909 No. 9 



NOTE ON THE ORNAMENTATION OF PERIGLYPTO- 



CRINUS PRISCUS. 



By William A. Parks, Ph.D., Associate Professor of 

 Geology, University of Toronto. 



With One Plate, No. III. 



This beautiful species was described by Billings in Decade 

 IV of Canadian Organic Remains as Glyptocrinus priscus. 

 Wachsmuth and Springer in their classical work "The Crinoidea 

 Camerata of North America," establish a new genus, Pcriglypto- 

 criniis, for the reception of those forms, otherwise like Glypto- 

 crinus, but in which the arms are biserial instead of uniserial as 

 in all members of the latter genus: the present species evidently 

 belongs to the new genus. 



Billings' description, while quite accurate except for the 

 statement that the plates of the cup are smooth, does not enter 

 into the detail necessary for the identification of species of 

 Glyptocrinus and its allies. The original figures also are small, 

 indistinct and destitute of the beautiful ornamentation charac- 

 teristic of the species. 



The description given by Wachsmuth and Springer* is 

 couched in the terminology adopted by those authors and is 

 quite adequate for the identification of the species; the profuse 

 ornamentation is however not mentioned nor does it appear in 

 the single figure which accompanies the text. The reason for this 

 omission lies in the fact that the type specimen from which both 

 Billings and Wachsmuth and Springer derived their figures is a 

 young and undeveloped example. The fortunate discovery of 

 two larger and more mature forms, which I cannot but believe 

 belong to this species, justifies some further remarks, particularly 

 with regard to the ornamentation of the plates of the cup. 



Judging from the figures of both authors, the size of the 

 type'specimen is about 13 mm. from the base to the point of 



*The Crinoidea C.-amerata of North A.menca p; 278 



