360 REPORT ON THE STATE CABINET. 



proboscidiform. The ovarian aperture is situated above the second 

 range of jolates, and is apparently more nearly at the summit of the 

 plate on the right, which has a somewhat different form from the 

 corresponding plate in Hemicosmites pyriformis. The plates of the 

 body are granulose and marked by strias parallel to the margins, 

 having the centre elevated in a low node from which there are 

 radiating ridges to the angles of the plate. 



Formation and Localitij . — In the Racine limestone of the Niagara group, 

 Eacine, Wisconsin. 



Among the collections from Racine, and associated with the preceding 

 species, there are several specimens of a peculiar form, apparently cysti- 

 deans, but of different structure from any described genus, which, from 

 the nodes or spines upon the surface of the species known, I propose to 

 name Echinocystites. 



GENUS ECHINOCYSTITES, n. g. 



Body subspheroidal, composed of four ranges of plates. The basal plates 

 are probably four, and are succeeded by two ranges of five plates 

 each and a series of dome plates. The mouth is central, with an 

 eccentric or lateral ovarian aperture. 



Echinocystites nodosus, n. s. 



PLATE XII, FIGS. 10, 11. 



Body subgiobose, base slightly protuberant in the centre ; basal plates 

 short. The five plates of the second range are large, forming part 

 of the basal curve, and extending up the sides; they are furnished 

 with strong nodes which are directed obliquely downwards. In the 

 third range the plates are of equal size with the second range, and 

 nodose in like manner ; the sides of the body between the nodes 

 being nearly straight in the vertical direction ; the nodes of the 

 lower range project a little beyond those above. Number and form 

 of the summit plates not determined. There is evidence of a central 

 aperture, which is probably the mouth ; while at the upper lateral 

 angles of two adjacent plates of the third series, and succeeded by 

 a plate of the fourth series, is situated the ovarian aperture. 



The specimens examined are casts of the interior, some of which retain 

 parts of the test, and preserve, in a greater or less degree, marks of the 

 structure. 



