Eight JSfew Species of llolocystlles from the Niagara Gronp. 120 



DESCEIPTION OF EIGHT NEW SPECIES OF IIOLO- 

 CY8TITES FROM THE NIAGARA GROUP. 



By S. a. Miller. 



Prof. James Hall, of New York, iu 1864, founded the geuiis IIolo- 

 cystites, and described four new species, and referred two previously de- 

 fined ones to the new genus. The next .year, Winchell and Marcy de- 

 scribed another species. All these were casts. 



The genus was defined as follows: " Body elongate, sub-c^'lindrical, 

 elliptical or sub-ovate, composed of numerous (six or more) ranges of 

 comparatively large plates, or of alternating series of large and small 

 hexagonal or polygonal plates; apertures at or near the summit, out of 

 them central or sub-central, the other eccentric; supported on a short 

 pedicel; sessile arms, none; free arms, unknown; no evidence of pecti- 

 nated rhombs." 



We now propose to define eight new species of Cystideans, and refer 

 them to this genus. Thej' are all well preserved, and show fully the 

 characters of the plates. 



The following characters are possessed in common by these species, 

 to wit: free arms, surrounding an ambulacral orifice; a mouth, eccen- 

 tric or removed to the side; and all the plates of the body poriferous. 

 Calling the side upon which the mouth is situated the ventral side, it 

 will be noticed that the dorsal side is alwa^'S the most ventricose. 



Some of the species possess a third openiaig. which is called the anal 

 aperture, and in three species, at least, this is found between the mouth 

 and ambulacral orifice. All the species were possessed of columns, 

 except, probably, H. hrauni. We have illustrated part of the section 

 of a column, showing the radiating lines upon the face of the plates, 

 and two roots. One of the roots is coiled around a column, and ter- 

 minates without branching, showing that it may have been a floater; 

 the other terminates in clumsy branches. This genus would, therefore) 

 seem to include species that were sessile, floating, or which possessed 

 a column, and attached b}' branching roots to foreign objects. We 

 have other roots, columns, and undescribed species from the same 

 rocks, that ma^' be illustrated in a future number of the Journal, and 

 throw further light upon the subject. 



The remarkable perfection of the specimens and their scientific import- 

 ance, will justif}^ a short statement of the history of their discover^-. 

 The credit of first discovering them is due to the zealous and indefati- 

 gable palii?ontologist, Mr. Fred. Braun. More than a year ago, he 

 collected a number of specimens in the lower part of the Niagara Group, 

 in Jefferson countj', Indiana. They were found less than seventy-five 



