96 CLEIOCRINUS. 



species, showing that the arms are fringed with closely packed pinnules. 

 This pinnulate structure, if it had been appreciated at the time, would 

 have presented a very serious obstacle to the inference of the genus to the 

 Ichthyocrinidse, in which entire group pinnules were thought to be wanting. 



Von Zittel, in his Grundziige der Palaeontologie, 1895, does not seem to 

 find any place for the genus ; nor does Eastman, in his annotated translation 

 of the work in 1900. 



Bather, in Ray Lankester's Treatise on Zoology, Part III., p. 191, places 

 the genus provisionally among the Flexibilia Impinnata, and gives the fol- 

 lowing diagnosis of its characters : " IBB and BB hidden by stem ; BR 

 small and separated by a large pentagonal interradial ; arms isotomous 

 to about VIIBr, and all appear to interlock and to be joined by close suture ; 

 post. IR supports a vertical series of anals, which reach the full length of 

 the arms." 



DESCRIPTION OF THE SPECIMENS. 



It having become necessary for me, in connection with a general investi- 

 gation of the group Flexibilia, to determine more definitely, if possible, the 

 systematic relations of this perplexing genus, I applied to Dr. J. F. Whiteaves, 

 Assistant Director of the Geological Survey of Canada, for the loan of the 

 specimens of Cleiocrimis in the Museum of the Survey at Ottawa. With the 

 most obliging courtesy this material was placed at my disposal, and was 

 promptly packed and shipped to me by Dr. II. Ami, Curator of the Museum, 

 with valuable notes giving detailed information as to the history of each 

 specimen. I find it difficult to adequately express my sense of obligation to 

 both these gentlemen for the cordial interest which they manifested, and 

 their careful attention to my wishes : and I desire to here record my pro- 

 found appreciation of the opportunity, for which I am indebted to them, of 

 an intelligent investigation of these unique fossils. 



The specimens reached me safely at Burlington in November, 1903. 

 They were found to consist of all of Billings's types figured upon Plate V. of 

 Decade IV., except 2a, and some important additional material since acquired 

 by the Canadian Survey. The latter included a crown of very large size, 

 but poorly preserved, and a stem thirty inches long with the root attached 

 that may belong to it ; also a fragment about seven inches long of a still 

 larger stem over one inch in diameter where not flattened. With the origi- 



