252 PROCEEDINGS OP THE ACADEMY OP 



Height of body, 0-12 inch ; hreadth ahout 030 inch ; hreadth of truncation 

 of thebase, 0-14 inch; length of arms, known to be at least l - 35 inch, but 

 probable more ; uniform breadth of do., 003. 



We very strongly suspect that this little crinoid will be found to be the type 

 of a new genus hearing somewhat similar relations to Synbathocrinus that 

 Pterotocrinus bears to Dichocrinus. The fact, however, tliat we have been 

 unable, after repeated trials, to make out the form and arrangement of the 

 plates composing the body, has caused us to place it provisionally, for the 

 present, as a subgenus under Synbathocrinus, with which it agrees exactly in 

 form and general habit, as well as in having the base composed of three 

 anchlyosed pieces. Even if it should, however, be found to possess precisely 

 the structure of Synbathocrinus so far as regards the body below the arm- 

 bases, we think its very peculiar character of having seven arms (instead of 

 only a single one) rising directly from the summit of each broa lly truncated, 

 first radial piece, a sufficient difference to entitle it to rank as the type of a 

 distinct subgenus, if not indeed of a distinct genus. The fact that all the 

 species of Synbathocrinus have, so far as known, but a single arm rising from 

 each ray, renders it improbable that there will be found intermediate grada- 

 tions in this character when a greater number of species are known. 



On one side of the specimen there is some appearance of a small cuneiform 

 anal piece resting upon the first radials, between two of the arm bases, as in 

 Synbathocrinus, though we are rather inclined to think this merely the base of 

 one of the arms folded in between the others so as to be hiddeu, excepting at 

 its base, by the closing together of the arms on each side. We have counted 

 this as an arm, and consequently, if it should prove to be an anal piece, there 

 would be but thirty-four arms, which would leave but six instead of seven 

 arms in one of the rays perhaps the anterior one. 



We have named this curious species after Mr. Charles Wachsmuth, of Bur- 

 lington, Iowa, its discoverer, and one of the most successful collectors at that 

 inter- sting locality. 



Locality and position. Burlington, Iowa, from the upper part of the Bur- 

 lington group, of the Subcarboniferous series. 



Cyathoceinus Farleyi, M. & W. 



Body, below the summit of the first radial pieces, rather deep cup shaped 

 or subglobose (oblique in the typical specimen), and composed of thick strong 

 pieces ; under side rounded. Base subdiscodial or depressed basin-shaped, 

 with a pentagonal outline, composed of unequal pentagonal pieces, very nar- 

 row at their connection with the column, and widening rapidly to their lateral 

 angles : all curved upwards at their superior outer extremities, Subradial 

 plates three or four times as large as the basal pieces, about as wide as long, 

 convex, and each provided with several irregular wart-like protuberances in 

 the middle ; four of them hexagonal, and one on the anal side heptagonal. 

 First radial pieces a little larger than the subradials, wider than high, and 

 each having a general pentagonal outline, but the superior lateral angles, 

 which usually curve inwards somewhat between the second radials, are more 

 or less truncated ; facet for the reception of the second radials large, or occupy- 

 ing about three- fourths the breadth of the upper side of each piece, and 

 on the outer side excavated downwards near half the length of the plate, 

 with a distinct outward slope. First anal piece about the size of the largest 

 basal pieces, quadrangular in general outline, but having two other inconspicu- 

 ous angles above, in consequence of small facets for the reception of three 

 small pieces in the next range, probably belonging to the vault ; resting 

 squarely upon the upper truncated side of the heptagonal subradial piece, 

 and connecting on each side with the adjacent first radials, above the horizon 

 of the summits of which it does not project. Surface smooth or finely 

 granular, with the exception of the irregular pustulose protuberances on the 

 middle of each subradial plate. (Arms aud column unknown.) 



Height to summit of first radial pieces, 0-bS inch ; breadth, 0-80 inch. 



[July, 



