Reviews — Wachsmuth ^ Sjyringer's Monograph on Crinoids. 41 



hastily. They are as follows : — The tube is closely connected 

 with the right posterior ray, it being up this side that the rectum 

 passes; in locrinus, Merocrinus, and Castocrinus, and, to a less 

 extent, in Heterocrinus, Ectenocrinus, and Ohiocrinus, the proximal 

 plate of the median row rests on the right posterior superradial ; ^ 

 in locrinus the articulation between the superradial and this 

 proximal plate differs from that between the superradial and 

 the first brachial only in size ;^ in many early Inadunata the 



1 Since I utilized this fact as an argument, "Wachsmuth and Springer have persisted 

 in denying its truth and have stigmatized my diagrams as incorrect. If it was not 

 true, why did they in " Eevision of Palfeocrinoidea, " iii, pp. 206, 207, wiite thus : — 

 In Ectenocrinus the r. post, "radial .... upon its upper side supports the 

 brachials, giving off laterally a small ventral tube ' ' ; and, in Heterocrinus ' ' the 

 smaller radial is transversely pentagonal, and resembles in outline a bifurcated plate 

 [axillare]. It supports upon its sloping right side the brachials ; toward the left the 

 ventral sac as in locrinus.''^ ? My diagram of Heterocrinus was, as stated at the time, 

 taken from the drawing of H. bellevillensis by W. R. Billings, whose description is 

 in complete accordance with the foregoing remarks, as pointed out in " Crinoidea 

 of Gotland, I" (1893), p. 72. I have no hesitation in saying that this mode of 

 description is absolutely correct. I have most courteously been given the opportunity 

 of studying a very large series of specimens of Heterocrinus and alKed genera from 

 the Trenton Limestone in the Walcott collection at the Museum of Comparative 

 Zoology, Harvard. In these x is invariably closely attached to r. post. R«, although 

 in many specimens it is clearly separated from 1. post. E. In several the ER have 

 become separated from one another, probably by pressui'e, and, when the posterior 

 interradius is the one exposed, it is always seen that the line of division passes to the 

 left and not to the right of x. This proves (so far as the consistent testimony of 

 hundreds is to be held as proof) that the union between x and r. post, E, is much 

 stronger than that between x and 1. post. E, even though the geometrical relations 

 of the two radials to x may occasionally be similar. But x rarely does lie 



Fig. 17. — Anal area of type - specimen of Heterocrinus 

 isndactylus in Dyer Coll. at Mus. Comp. Zool., 

 Harvard. Said by S. A. Miller to be syn. of 

 Ohiocrinus compactus. This shows far closer con- 

 nection of X with r. post. Es than with 1. post. E. 

 (Enlarged.) 



symmetrically to the adjacent radii : it is nearly always towards the right of the 

 interradius ; its two sides abutting on r. post. Es and its IBrj are straight and meet 

 almost at a right angle, whereas the side or sides abutting on 1. post. E and its IBri 

 generally form a continuous ciuwe rather than an augle ; in all cases where there is 

 any swelling of the radials, or any development of axial folds, then x is clearly 

 connected with the swelling or fold of r. post. E, and in no way with that of 1. post. R 

 (Fig. 17). These statements, which may be verified by anybody, refer specially to 

 the HeterocriiudEe, though many of them hold good for species not in that family. 



2 Wachsmuth and Springer again criticize my application of the term ' axillary ' 

 to the r. post. Es of locrinus. They take no notice of mv explanation (" Brit. Foss. 

 Crin. Ill," Ann. Mag. Nat. Hist. [6], vi, Sept. 1890, p."228). But there is more to 

 be said for the application than I was then aware of. The accompanying drawings 

 (Fig. 18) were made from specimens of locrinus subcrassus in the Mus. Comp. Zool. 

 Harvard. I shows the iuferradial, superradial, and first brachial of the r. post, 

 radius from inside ; the anal tube is broken off, but its ventral groove is seen passing 

 down the Rs and coalescing in the Ei with the ventral groove of the arm. II shows 

 the articular surface of E* with the dorsal ligameut-fossa, the two muscle -plates, 

 and the already dividing ventral groove. Ill and IV show the two upper articular 



