OCCURRENCE OF THE CRINOID GENUS APIOCRINUS 



IN AMERICA 



By Frank Springer, 

 Associate in Paleontology, United States 'National Museum 



The genus Ajrlocrinus is one of the most conspicuous of Mesozoie 

 crinoids, hitherto known only from Europe, where it is found as a 

 typical fossil in the upper Jurassic (Oolite) of England, France, 

 and Switzerland. It was first described and figured by Parkinson ^ 

 under the name " Pear Encrinite," in allusion to the pronounced pear 

 shape of the calyx. In 1820 Schlotheim designated Parkinson's 

 species according to the rules of binomial nomenclature as Byncrlnites 

 parkmsoni, nearly all crinoids then being known as Encrinites. 



In the following year J. S. Miller in his Natural Hist<)ry of the 

 Crinoidea, 1821, proposed the genus Apiocrinus for the Parkinson 

 fossil, to which he gave a new specific name, A. rotundus; this was 

 not accepted because clearly a synonym of Schlotheim's species. 

 Thus the name became established as Apiocrinus (Apioerinites) 

 parkinHoni (Schlotheim) for the species by Avhich the genus is best 

 known in collections, through specimens from the Bradford clay 

 of England, and from various localities in England and France. 

 The genus is abundant and widely distributed, 27 species having 

 been described, 15 from France, 2 from England, and 10 from 

 Switzerland and adjacent regions. The descriptions of most of them 

 nuiy be found in the works of D'Orbigny, Quenstedt, and De^Loriol. 



Apiocrinus is the type of a very distinct family which has con- 

 tinued from the Jurassic to the present time; and the genus itself, 

 in its typical forms, is strongly differentiated from its fellows by 

 the fact that the stem, which is round and without cirri, is in its 

 upper part greatly expanded into a proximal conical enlargement 

 continuous with the sides of the calyx, so that there is no line of 

 demarcation between them. Its characters in detail are well shown 

 in the figures of ^4. paj^kinsoni in Zittel-Eastman's Text-book of 



^ Organic Remains of a Fonner World, 1808, vol. 1, p. 208, pi. 10, figs. 1-8, from 

 Bradford, near Bath, England. 



No. 2590. — Proceedings U. S. National Museum, Vol. 67, Art. 18. 



21513—2.' ] 



