BATOCEINID^. 529 



catm- Co., Tenn., and there is but little doubt that the one described by 

 Roemer, and provisionally referred by him to Saccocrimis sj>ecwsus Hall (Silur. 

 Fauna "West. Tenn., Plate 3, Fig. 3), represents the same species. We have 

 in our collection several specimens from that locality with four arms to each 

 ray, but none with three in the posterior rays, as shown in Eoemer's figure 

 which is said to be a restoration. The specimen described afterwards by 

 Hall is a natural cast in the Ohio State Cabinet. 



Periechocrinus Howard! (S. A. Miller). 



1892. Saccocrimis Roimrdi — S. A. Millee; Adr. Sheets IStli Rep. Gaol. Surv., Indiana, p. 30, Plate 5, 

 Figs. 3 and 4. 



A small species. Calyx higher than wide, broadly truncated at the base, 

 and but slightly expanding, so as to be almost subcyhndrical to near the 

 arm bases, which bend abruptly outward. Plates tumid, without ornamen- 

 tation ; suture lines beveled. 



Base short, forming a broad rim, which is squarely truncated at the bot- 

 tom ; its diameter equal to two thirds the greatest width of the cup. Eadials 

 more tumid than the other plates, about as wide as long. First costals two 

 thirds the size of the radials; the second much smaller. Distichals three, 

 directed almost at right angles to the axis of the calyx ; supporting the free 

 arms. Arm openings ten, arranged in pairs, each pair separated by numer- 

 ous interradial plates, which connect with the plates of the tegmen. Inter- 

 radial areas composed of two or three large tumid plates, followed by smaller 

 ones. In the type specimen there is but one large plate in the second row 

 at the regular sides, probably the usual two being consolidated. Anal area 

 much wider and somewhat flattened, the plates rising almost vertically. Anal 

 plate followed by 3, 3, and 5 interbrachials ; those of the latter row irregu- 

 larly arranged. Ventral disk almost on a level with the arm bases, only the 

 central part a little convex ; composed of numerous small plates without defi- 

 nite arrangement. The anal opening marginal. 



Horizon and Localiiy. — Niagara group ; St. Paul, Shelby Co., Ind. 



Remarks. — Being unable to obtain the type specimen, our description is 

 made after Miller. 



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