1896.] Geology and Paleontology. 821 
us believe. The only real difference is that in Meek’s figure there is 
above II Br, a non-pinnulated brachial separating two pinnule-bearing 
arm-plates. The same extra plate is shown in figure le. The intercala- 
tion of a non-pinnulated plate of this kind is of common occurrence 
among crinoids, and should not excite any wonderment, let alone ad- 
verse criticism. In Uintacrinus this is of frequent occurrence, not only 
in different specimens but also in the different arms of the same indi- 
vidual. Mr. Bather himself shows that two out of the ten examples 
which he examined do not agree with his general formula. If his 
observations could have been extended it might have been found that 
one in three is just about the proportion of the individuals that do not 
agree in this respect. It might be added parenthetically that of 200 
specimens of Uintacrinus that have been personally examined, fully 
one-half of them appear to vary in a similar way in the mode of pinuu- 
lation. 
Granting then that Meek’s original figure is correct in every detail 
and that figure la of Professor Clark’s plate represents the same speci- 
men, the differences are practically immaterial. Professor Clark’s work 
not only does not violate the fundamental law of pinnulation but is 
essentially correct so far as typifying the species. The very object of 
adding an enlarged view of another specimen (figure 1c) was to make 
more clear the arrangement of the pinnules, since the convexity of the 
principal specimen and its distortion somewhat misrepresented these 
points, The same may be said of I[Br, in figure 1c. Usually from 
II Br, on, the pinnules are turned in or are covered by the matrix if the 
specimen is not carefully cleaned, and consequently do not show from 
above. That II Br, should be visible on one arm and not on another 
is not strange, and not necessarily incorrect. 
Regarding Mr. B. H. Hill’s diagram the formula given by Mr. 
Bather is probably correct for the figure ; but, as he has stated, it is dith- 
cult to decide the question owing to the “ rather peculiar mode of repre- 
sentation.” It seems hardly possible that this diagram correctly 
represents the pinnulation of the specimen from which it was taken, 
and the entire disagreement of the corresponding plate faces when sepa- 
rated would further indicate that the figure is, as stated by Mr. Bather, 
“hopelessly incorrect,” or illustrates a new species.—C. R. Keyes. 
Geological News.—Patxrozorc.—From data recently compiled, 
Prof. C. R. Keyes estimates the total maximum thickness of the Paleozoic 
rocks in the middle part of the central Mississippi basin, that is, in the 
neighborhood of the Missouri River, between Kansas City and the Iowa” 
