1886.] NATURAL SCIENCES OP PHILADELPHIA. 177 



in all later Poteriocrinidse. Prof. Trautschold overlooked the 

 only important distinction between liis form and Poteriocrinus. 

 His species has a single anal plate within the dorsal cup, while 

 Poteriocrinus has three. However, in this character Synypho- 

 crinus resembles Graphiocrinus, and especially the subgenus 

 Bursacrinus, which has the same general form, a similar funnel- 

 shaped underbasal cup, and also branching arms. 



It is possible that Poteriocrinus meekianus Shum. (Swallow's 

 Geol. Rep. Missouri) is a Bursacrinus, but it may be a Barycri- 

 nus. Only the dorsal cup is known. 



Additional species : 



*]881. Bursacrinus cornutus (Trautschold), Synyphocrinus cornutus, Bull. Mos- 

 cow, Ueber Synyphocrinus. Berg-Kalk. Mjatschkowa, Russia. 



(?) Subgen. PHIALOCRINUS Trautschold, Rev., i, p. 124. 



CEKIOCRINUS White (not Koenig). i 



(Emend. W. andSp.). 



1880. White, U. S. Geol. Surv. under Hayden for 1878. Paleont., Nos. 

 2-8 (Author's Ed., p. 12). 

 Syn. Euijachycrinus (in part), "W. and Sp., 1878 ; M. and W., 1873. 

 Syn. Eriosocrinus (in part), White, 1879. 



Ceriocrinus is very interesting as representing a link between 

 the unsymmetrical Eupachycrinus and the symmetrical Erisocri- 

 nus. The three are very similar, and some of the species cannot 

 be separated even specifically, unless the azygous side is exposed. 

 We were at first inclined to follow Meek and Worthen in placing 

 species with one and three anal (azygous) plates under Eupachy- 

 crinus, which has three in its typical form, and to separate those 

 only which have no azygous plates within the dorsal cup. Our 

 way of disposing of this question was contrary to the rules laid 

 down by ourselves among other groups, but we took it to be a case 

 of rapid and extravagant development, and as such possibly only 

 of specific value. A similar view, but in a somewhat different 

 direction, was taken by Dr. White, who placed in his Ceriocrinus 

 species having an " anal plate " between the radials (none below), 

 together with species in which a similar plate is supported by the 

 radials (beyond the limits of the dorsal cup), and he ranked 

 Ceriocrinus as a subgenus of Erisocrinus. 



^ Koenig' s genus has not been accepted (see De Loriol, Monogr. des 

 Crin. Foss. de la Suisse, 1877, p. 61). 



