982 



MB. F. A. BATHER OTT UINTACRINTJS. 



[Dec. 17, 



only do the two other branches agree with the law, but this arrange- 

 ment violates the fundamental law of alternation of pinnules, so 

 that I have little doubt the figure is incorrect. Clark's pi. i. fig. Ic 

 (PI. LVI.) agrees with the law except for the fact that IIBr^ 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 my 

 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 Clai'k'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. 7. 



Fig. 6. 

 Pig. 7. 



-TJintacrinus socialis, part of Brit. Mua. E 6527, b, showing fixed 



distichals and pinnules. Natural size. 

 -Uiiitaei-mun socialis, part of Brit. Mua. E fi.527, p, showing fixed 



distichals and pinnules, interbrachials, and interdistichals. Natural 



size. 



made by Mr. C. E. 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 ; IlBr,, outer ; IIBrg, inner ; IIBr^, outer ; IIBr^, 

 inner; lIBr^, outer; IIBr,, inner; IIBr^, outer; lIBrg, inner. 

 Now this is so absolutely inconsistent with the law, with the 

 type-specimens, with known variations, and with the general 

 structure of (J. 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 euoitgh. 



V 



