342 Mr. F. B. Meek on the Genus Liclienocrinus. 



nulse, as well as of the most minute ambulacral or other open- 

 ings, save the minute perforation into the slender column-like 

 appendage, and the attachment of this appendage to the free 

 side of the firmly adhering disk are also very anomalous fea- 

 tures, if we view this disk as the body of a crinoid. 



On examining one of these fossils, one of the first questions 

 that suggests itself is, what can be the nature of this long 

 slender appendage, not more than from four to eight or ten hun- 

 dredths of an inch in diameter and several inches in length ? 

 Is it homologous with the so-called proboscis or ventral tube 

 of other crinoids, or with the column of the same ? Prof. Hall 

 evidently entertained the former opinion at the time he wrote 

 the diagnosis quoted above, though I was informed at Cincin- 

 nati that, after seeing other specimens than those from which 

 his diagnosis was written, he inclined to the opinion that it is 

 a column. That one or the other of these views is correct 

 would almost necessarily seem to be the case ; and yet there 

 would appear to be rather strong objections to both of these 

 conclusions, if we view the disk as the body of a crinoid. In 

 the first place, if a column, why should the body, instead of 

 being, as usual, attached by it, be always (when not acciden- 

 tally detached) found growing firmly by the whole opposite 

 side to foreign bodies, and this long- appendage in all cases be 

 left dangling free and, if viewed as a column, apparently use- 

 less ? Again, if a column, connected with the free side of the 

 body of an attached crinoid, how are we to account for the 

 fact that no traces of any other opening than that passing in 

 through this appendage can be seen, even by a careful exami- 

 nation under a magnifier, in any part of the body ? In addi- 

 tion to this, it does hot connect with the disk by a series of 

 basal piecesj»as is usually the case with the connexion of the 

 column of a crinoid or cystoid to the body of the same, but, on 

 the contrary, the plates of the disk diminish in size inward, 

 and pass by easy gradations into those forming the base of 

 this long appendage. 



On the other hand, if we proceed to view this appendage as 

 a proboscis, or ventral tube, connecting with the ventral side 

 of the body, we are met by the objection of its extreme pro- 

 portional length, slenderness, flexibility, and the fact that it 

 seems to taper off nearly to a point at its free end. In Mr. 

 Dyer's collection there is a piece, apparently of the free end 

 of this organ, about an inch in length, and agreeing exactly 

 in size, form, and structure with that of L. Dyeri^ that is 

 broken at one end and tapers to a slightly blunted point at the 

 other end, which is composed of very minute pieces drawn to- 

 gether. In other examples, where three or four inches in 



