34 The Ohio Journal of Science [Vol. XXI, No. 2, 



Most cystids from the Cedarville dolomite of Ohio evidently 

 are related closely to those of the Racine dolomite of Wisconsin 

 and Illinois, described by Hall in 1868 in the 20th Report 

 of the New York State Cabinet of Natural History. Several of 

 these Racine species were restudied by Schuchert in his paper 

 on Siluric and Devonic Cystidea and Camarocrinus, published in 

 the 47th volume of the Smithsonian Miscellaneous Collections 

 in 1904, but some of the other Racine species demand equally 

 detailed consideration and the results of recent studies on several 

 of these species are incorporated here. 



As a result of these studies we now know the appearance of 

 the exterior of the theca of Coslocystis subglobosus (Hall). It 

 has been learned that Aethocystites and Lysocystites are identical 

 genera, the former being founded on the exterior of one species, 

 and the latter on the interior of a second species, but both 

 species are congeneric. Crinocystites chrysalis, moreover, has 

 been identified as the anal tube of some species of Eucalypto- 

 crinus. 



It is now recognized that the figures accompanying the 

 original descriptions of Lysocystites nodosus and Crinocystites 

 chrysalis were drawn in inverted positions. After some difficulty it 

 has been found possible to diagram the plate system of the type of 

 Ccelocystis subglobosus, confirming the identifications made by 

 Schuchert, and considerable variation has been observed in the 

 general form of different specimens and in the outlines, arrange- 

 ment, and number of the plates. In Holocystites alter?iatus, the 

 intercalation of supplementary plates has been made the subject 

 of further study. 



Only one species of blastoids is known from the Cedarville 

 dolomite of Ohio, Troostocrinus subcylindricus (Hall and Whit- 

 field), published in 1875, in volume 2 of the Paleontology of 

 Ohio. The occurrence of Troostocrinus is noted also in the 

 Racine of the Chicago area, the Bainbridge of eastern Missouri, 

 and the top of the Laurel limestone of southeastern Indiana. 



The Ohio species, Eucaly ptocrinus proboscidialis Miller, is 

 refigured to show its close relationship to Crinocystites chrysalis 

 Hall. 



The problematical organisms described as Cyclocystoides, 



and usually regarded as Edrioasteroids, show variations in 



structure suggesting the presence of several groups of generic 



ank, and for two of these groups the terms Narrawayella and 



Savagella are proposed here. 



