316 The American. Geologist. November, 1896 
tion of the work devoted to corals ; for when we come to the Bryozoa, 
a subject which has been largrly rewritten by Uh-ich, we find the fistu- 
liporoids and monticuliporoids separated from their fellows of the old 
Tabulata and from each other, and ranged under different ordinal di- 
visions of this interesting class of Molluscoidea. No better disposition 
of Heliolites and Plasmopora is proposed than to leave them with the 
recent Heliopora under Alcyonaria. 
With some slight modifications, both in taxonomy and the termin- 
ology of the structural elements, the crinoids have been revised in ac- 
cordance with the latest published deductions of Carpenter, Bather, 
and Wachsmuth and Springer. In no group of organisins has a knowl- 
edge of the significance and homologies of structural elements pro- 
gressed more rapidly in recent years than among crinoids. In no group 
have changes of views among specialists followed each other in such 
quick succession. It may not be safe to say that further progress, in- 
volving future modifications in taxonomy, is improbable; but it may be 
affirmed that the scheme of classitication presented by the work before 
us is up to date, and represents the fullest, latest, best information on 
the subject. 
The other classes of the Echinodermata may not have fared as well 
as the Crinoidea, but all are treated fully and in accordance with the 
best knowledge at hand. Billings' genus Glyptocystites seems, however, 
a little out of place in the Caryocrinidae, and the American Devonian 
genus of the Cystoidea, Strobilocystites, might have had a place in a 
text-book that will be largely used on this side of the Atlantic. 
The Bryozoa have been revised by Ulrich as already noted; and that the 
classification of the Brachiopoda is in accord with the latest determina- 
tions of structural affinities in this important group is attested by the 
fact that the chapter on the subject was revised and largely re- written 
by Schuchert. The conclusions of Hall and Clark in Paleontology of 
New York, Vol. VIII, are somewhat closely followed. 
The work undertaken by Dr. Eastman and his collaborators is one of 
great magnitude, and if the remaining portions of the text-book reflect 
the latest knowledge of the several parts of the science as does the one 
already issued, jjaleontologists, not only in English speaking countries, 
but throughout the world, will be placed under lasting obligations. 
s. c. 
On tlie Vertebral Column, Fins, and Ventral Armo^ling of Dinich- 
thys. By Bashford Dean (Trans. N. Y. Acad. Sci., vol. xv, pp. 157- 
163. pi. vii, viii, 1S96.) By iiieans of this paper, which repi-esents the 
author's study of a unique specimen of Dinichthys in the collection of 
Dr. William Clark, our knowledge of this interesting genus of fossil 
fishes is greatly increased. The vertebral axis and supports for the 
dorsal and ventral fins are here described for the first time, and import- 
ant relations are pointed out between them and the conditions existing 
in Coccosteus. It is noted that the dorsal fin occupies the same relative 
position in Vjoth genera, but it is "smaller and more delicate in Dinich- 
thys, the latter character being directly opposed to what might have 
