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Show 982 MR. F. A. BATHER ON UINTACRINUS. [Dec. 17, only do the two other branches agree with the law, but this arrangement violates the fundamental law of alternation of pinnules, so that I have little doubt the figure is incorrect. Clark's pl.L fig. Ic (PL LVI.) agrees with the law except for the fact that H B r 9 in the right-hand branch bears an inner pinnule, while in the left-hand branch it bears none. I have little doubt that this pinnule is incorrect. It is not merely because they are inconsistent with m y own observations that I cast doubt on Prof. Clark's figures; but because they are inconsistent, each in itself, each with his other figures, and each with his own statements on p. 23. There is also internal evidence to show that Clark's fig. la of pi. i. is drawn from the same specimen as Meek's fig. B. If Meek is, as there is reason to believe, correct, then Clark is wrong. It is only fair to Prof. Clark to remember that the drawings here criticized were Fig. 6. Fig. 7. Fig. 6.- Uintacrinus socialis, part of Brit. Mus. E 6527, b, showing fixed distichals and pinnules. Natural size. Fig. 7 . - Uintacrinus socialis, part of Brit. Mus. E 6527, p, showing fixed distichals and pinnules, interbrachials, and interdistichals. Natural size. made by Mr. C. B. Keyes, whose work is usually trustworthy, and whose acquaintance with fossil crinoids is considerable. Mr. B. H . Hill's (9) diagram shows the following arrangement, so far as I can decipher his rather peculiar mode of representation :- IIBrj, none; IIBr,, outer; IIBr3, inner; IIBr4, outer; IIBr3, inner; HBr6 , outer; IIBr7, inner; IIBr8, outer; IIBr9, inner. N o w this is so absolutely inconsistent with the law, with the type-specimens, wdth known variations, and with the general structure of U socialis, that it can only be supposed either that Mr. Hill's diagram is hopelessly incorrect, which I should be sorry to think, or that he has unwittingly figured a new species, which I find it hard to believe, especially as Prof. Williston (9) shows himself fully alive to the possibility of there being more than one American species, and would have noted the fact quickly enough. |
