Dec, 1920] Cystids and Blastoids 67 



Racine horizon. Considering^ the close resemblance between the Racine 

 faunas of Illinois and Wisconsin and the Cedarville fauna of Ohio, this 

 Bridgeport specimen might be expected to show close affinity to 

 Trooslocrinus subcylindricus (Hall and Whitfield), from the Cedarville 

 dolomite. Compared with the latter it presents the following differences: 



The radial sinuses are more narrow, varying from 1 mm. to slightly 

 over 1.5 mm. in width. The triangular areas between these sinuses are 

 relatively shorter, have a somewhat wider apical angle, are only slightly 

 concave, and are more strongly and more abruptly inflected toward one 

 another. Near the lower end of the radial sinuses the cross-section of 

 the theca is pentagonal, the lower half of the radials being angular along 

 the median line, but their curvature along this line is not outward on 

 approaching the lower end of the sinuses, as in Troostocrinns subcylindri- 

 cus. All parts of the theca are relatively shorter than in the latter 

 species, the result being a blunter top, and a more rapidly attenuating 

 base to the theca. 



Compared with Trooslocrinus sanctipaulcnsis, the theca is similar to 

 the figured specimen, in the shorter form and resultant outline, in the 

 narrowness of the radial sinuses, and in the absence of any outward 

 curvature of the median part of the radials just beneath the lower end 

 of the radial sinuses. It differs in the triangular areas between these 

 sinuses being shorter and less abruptly curved inward. 



Additional specimens will be needed to discriminate this form if it be 

 distinct from those already described. 



Ifl. Crinocystites chrysalis Hall. 

 (Plate I, Figs. 2 A, B; 3 A, B.) 



Crinocystites chrysalis Hall, 20th Rep. New York State Cab. Nat. Hist., 1868, 

 p. 318, Pl.'l2a, Figs. 10, 11. 



The type of Crinocystiles chrysalis (Plate I, Figs. 2 A, B), from the 

 Racine dolomite at Racine, Wisconsin, is preserved in the American 

 Museum of Natural History, in New York City. As figured by Hall, 

 this type consists of a clavate, moderately curved body; the sutures 

 between the plates are represented, correctly, but there are no arm sup- 

 ports, the specimen having been incorrectly interpreted in this respect. 

 Both of the figures presented by Hall are inverted from their natural 

 position. 



Arthur W. Slocom, the curator of the Walker Museum at Chicago 

 University, called my attention to the fact that Crinocystites chrysalis 

 was merely the cast of the interior of some other body whose exterior . 

 aspect was very different. This was shown by specimen 22914 in Walker 

 Museum, which came from the same horizon and locality as the type 

 of Crinocystites chrysalis. Prof. Stuart Weller at once recognized the 

 similarity of this specimen to Eucalyptocrinus proboscidialis Miller 

 (Plate I, Fig. 4) from the Cedarville dolomite, at Pontiac, Ohio (Jour. 

 Cincinnati Soc. Nat. Hist., 5, 1882, p. 224, PI. 9, Fig. 2). Formerly 

 Pontiac was the seat of a lime industry. It was a railroad station, five 

 miles south of Sidney, in Shelby County. Here the Racine phase of the 

 Cedarville dolomite is exposed. 



