268 PALAEONTOLOGY OF OHIO. 



columns of Crinoids, which they closely embrace and incrust ; and they 

 might readily be mistaken for a species of Aulopora, unless care were ex- 

 ercised. The species is nearly allied in essentials to the two preceding ; 

 but it is distinguished by its constantly forming thin crusts, by its larger, 

 more prominent, and more closely and irregularly arranged cells. 



Position and locality : Cincinnati group. Cincinnati. Collected by Mr. IT. P. James. 



HiPPOTHOA INFLATA, Hall. 



Plate 25, figs. 1,16. 

 Alecto inflata, Hall; Pal. N. Y., Vol. I., p. 77, pi. 26, figs. 7a, 7b. 



Polyzoary creeping, adnate, branched, and forming a close but irregu- 

 lar network. Branches linear ; cells uniserial, pyriform, each springing 

 by a contracted base directly from the cell below; about four cells in the 

 space of one line. Cell-mouths smaller in diameter than the expanded 

 end of the cell, sub-terminal, and placed more or less distinctly on the 

 front face of the ceil. 



Though in some respects resembling some of the species of Alecto, I 

 think there can be no hesitation in referring this beautiful species to the 

 genus Hippothoa, Lamouroux, with which it agrees in the form of the 

 cells and the position of the cell-mouths. It is very readily distin- 

 guished from the species of Alecto just described, by the fact that the 

 cells are not at all immersed, by the fact that each cell springs directly 

 from another, by the cells being strictly uniserial, and by the position of 

 the cell-mouth on the front face of the swollen cell. The cells are distinctlj" 

 pyriform in shape, attenuated below, with a smooth surface, the aper- 

 ture being orbicular or oval and destitute of notches or sjDines. The net- 

 work formed by the polyzoary is usually a very close one, the branches 

 being given off from the sides of the cells, usually at intervals of from 

 half a line to two-thirds of a line. 



All the examples of this species which I have seen are parasitic upon 

 StrophonienOj alternata. Hall's specimens are from the Trenton limestone, 

 but there can be no doubt as to their identity with ours. 



Position and locality : Cincinnati [group, Cincinnati. Collected by Prof. Edward 

 Orton and Mr. U. P. James. 



