170 PALiEONTOLOGY OF OHIO. 



but only a granule, is visible. The first anal plate is small, with two or 

 three granules above it. The patelloid plates of the rays, and their 

 divisions, are distinctly visible throughout all parts of the body. 



The column, near its summit, is composed of the thin joints charac- 

 teristic of species of this genus, with longer and irregular joints below, 

 sometimes prominent in the middle, giving them an annulated char- 

 acter. 



In this species we have the characters of the lower part of the body 

 seen in some of the Carboniferous species of the age of the Keokuk lime- 

 stone, at Crawfordsville, Indiana, where there are no interradial plates, 

 and the anal area has but one distinct plate. In those species the rays 

 are continued above the first bifurcation, throwing off lateral armlets, 

 but not properly bifurcating. All the Carboniferous species, with regu- 

 larly bifurcating arms, as in this one, have interradial areas, with 

 numerous plates. This species, therefore, combines in part the Charac- 

 ters belonging to two Carboniferous types of the genus, but possesses 

 neither of them fully. 



A specimen from the Chemung group, at Porestville, Chautauqua 

 county, New York", exhibits all the characters shown by this species, so 

 far as can be seen in a single individual, one side of which is imbedded 

 in the rock. 



Formation and locality : In shales of the Waverly sandstone group, at Richfield, 

 Summit county, Ohio. 



FORBESIOCEINUS TARDUS. 



Plate 12, fig. 2. 



Forbeaioerinus lobatus, var. tardus; 17th Rept. on N. Y. State Gab. of Nat. Hist., p. 56, 

 1864. Extr. published November, 1863. 



Body somewhat moderately expanding above the base, and deeply 

 lobed. Basal and sub-radial plates undetermined, very small. Primary 

 radials, three in each ray, so far as seen, the third one prominent, tumid 

 or sub- nodose in the center. Secondary, or first supraradials, from three 

 to five in each division ; above this the number of plates is very irreg- 

 ular. 



Arms bifurcating two or three times above the the third supraradial, 

 and rapidly diminishing in size. 



On the anal side a single narrow elongate plate is visible, the remain- 

 der of the anal area undetermined. 



The plates of the body are very convex along the middle exteriorly, 



