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



Wellerocystis Gen. nov. 



Amygdalocystites and Canadocystis. — The genera Amygdalo- 

 cystites and Canadocystis agree in having two divergent main 

 food-grooves which curve toward their distal ends in a more or 

 less distinctly dextral direction. These food-grooves are sup- 

 ported on single series of plates, which rise more or less abruptly 

 along the convexly curved outer side of the rays and which 

 support on this side a single series of brachioles, while the main 

 food-grooves occupy the concavely curved side of the rays. In 

 both genera, the anal opening lies exterior to the convexly 

 curved side of the nearest one of the two rays, but near a vertical 

 plane passing through the oral aperture and parallel to the 

 proximal straighter part of the rays. 



Wellerocystis. — In a cystid found by Prof. Stuart Weller in 

 the Kimmswick limestone of eastern Missouri a closely similar 

 structure is found. Its general aspect is nearest that of Amyg- 

 dalocystites, but there are 3 instead of 2 rays, that one of the 

 primary rays which is most distant from the anal opening 

 branching within a short distance from the oral aperture, the 

 new branch being added on the left side of the primary ray. 

 Moreover, the anal opening, as exposed in the type specimen, 

 lies within the area enclosed by the concavely curved side of 

 the undivided ray. From Amygdalocystites this cystid differs 

 in its ovoid form, and in the absence of radiate ribbing on the 

 thecal plates, the latter being gently convex and minutely 

 granular. From Canadocystis it differs in the different location 

 of its anal opening, in the branching of one of its rays, and in 

 the more decurrent growth of the tips of these rays. However, 

 if the Kimmswick specimen be so oriented that its anal opening 

 is on the same side as in Canadocystis, then the attachment 

 area for the column in both cases will be found on the diagonally 

 opposite side of the basal part of the theca. 



Genotype. — Wellerocystis kimmswickensis Sp. nov. Genus 

 named in honor of Prof. Stuart Weller, in recognition of his 

 many important contributions to American Paleontology. 

 Genotype formed by the Kimmswick cystid mentioned above. 



In the United States National Museum at Washington there 

 is another undescribed Kimmswick cystid, collected by Dr. 

 E. O. Ulrich, apparently congeneric with Wellerocystis kimms- 

 wickensis, but with each of the two primary rays having two 

 additional branches, thus forming a total of six. 



