90 PROCEEDINGS OF THE ACADEMY OF 



supplementary pore pieces unknown ; lancet pieces apparently not visible 

 externally, unless it is along the bottom of the mesial furrow. 



Summit, when the minute pieces that doubtless closed the central region 

 are removed, with a pentagonal opening of about the size of the anal aperture ; 

 so-called ovarian pores very small, and situated one on each side of each 

 interradial piece, and two others doubtless as usual opening into the anal 

 aperture, which is nearly circular and much larger than the pores. 



Surface finely granular, the granules being smaller and more crowded on 

 a lanceolate area, extending up the radial pieces between the pseudo-amlnila- 

 cra, and terminating just before reaching the interradials, and on each side, 

 and above this space. 



Height of body, 0-30 inch; breadth, 0-28 inch. 



This little species might be mistaken for a small specimen of O. melo, by a 

 hasty observer. It may be readily distinguished, however, by its longer inter- 

 radial pieces, less numerous and proportionally larger pore pieces, much more 

 prominent pseudo-ambulacra, and particularly by not having even a trace of 

 a linear furrow along up the sutures separating the radial pieces, and these 

 pieces flat instead of convex across between the pseudo-ambulacra. The little 

 projecting points at the bases of its pseudo-ambulacra are also directed more 

 downward. 



Locality and position. Upper part of the Burlington group, Burlington, 

 Iowa. Lower Carboniferous. No. 397 of Mr. Wachsrauth's collection. 



Geanatoorinus neglectus, M. and W. 



Body small, varying from oval to subglobose. Base slightly projecting, 

 pentagonal in outline. Radial pieces scarcely equaling two-thirds the entire 

 length, and deeply divided by the pseudo-ambulacral areas. Interradial pieces 

 more than one-third the length of the body, cuneate-subtrigonal in form. Anal 

 piece of about the same size as the interradials, but its upper extremity is erect 

 and distinctly projecting, so as to form around the anal opening protuberant 

 margins. Pseudo-ambulacral areas narrow, with nearly parallel sides, almost 

 equaling the entire length of the body, nearly as prominent as the slightly 

 raised margins of the radial pieces on each side; pore pieces twentj^-five to 

 thirty on each side of the mesial furrow ; supplementary pore pieces unknown ; 

 lancet pieces apparently not visible externally. 



Mesial opening of the summit very small ; so-called ovarian apertures minute 

 and situated one on each side of the interradial pieces ; anal opening compara- 

 tively large, with very prominent margins. 



Surface of the radial plates between the pseudo-ambulacral areas longitudi- 

 dinally granulo-striate, while that of the interradial and anal pieces is marked 

 in the same way transversely with a downward curvature. 



Length of one of the oval specimens, 0-36 inch ; breadth, about 0-28 inch ; 

 breadth of pseudo ambulacra 05 inch. Length of a smaller, proportionately 

 shorter specimen, 0-28 inch ; breadth, 0-25 inch. 



This is another species having much the general appearanre of G. melo, from 

 which, however, it is at once distinguished by its comparatively much larger 

 interradial and anal pieces, flat spaces between the pseudo-ambulacra, without 

 any furrow along the mesial suture, and its more protuberant base and anal 

 pieces. 



It is more nearly allied, however, to the last described species in several of 

 these characters, though sufiiciently distinct to be readily separated on compa- 

 rison. For instance, its anal and interradial pieces are nearly twice as large as 

 in that species. Again, its base is proportionally two or three times as large, 

 and so protuberant as to be seen in a side view, instead of being concave ; 

 while its pseudo-ambulacral areas do not extend so far down, and the little 

 projections of the radial pieces at the lower extremities of these areas point 

 out horizontally, instead of being directed nearly downward, like five little 



[April, 



