92 The American Geologist. August, 1902. 
species ; and that the arms are isotomous. The rays in this 
specimen are unusually long, and the patelloid processes in 
the proximal plates scarcely visible, giving it a strong sup- 
erficial resemblance to some forms of On\chocri)uis. Yet 
the arms branch throughout by nearly equal bifurcations as 
in Forhcsiocriiuis and Taxocrinus, and not by means of lat- 
eral ramules as in Onychocriiuis. This mode of bifurcation 
may be seen in De Koninck's figure 2a. The genus Forhcs- 
iocriiuis, therefore, being really founded on good distinc- 
tive characters clearly set forth in the description, though 
not the one specially mentioned by the authors, is entitled 
to stand, — the type being, as before stated, F. iiobilis De 
Koninck and Le Hon, and not Taxocrinus iwbilis Phillips. 
A further question has to be considered in connection with 
Taxocrinus: — The Upper Silurian species, T. tiihcrcidatus 
Miller, from Dudley, England, has been hitherto cited as a 
good representative form of the genus, and is one of the four 
species referred to it by Phillips. It now appears, from a 
study of a large series of specimens, that it belongs to a 
type so very different from the other species as to require the 
recognition of a new genus for its reception. It has what 
looks like an extra primibrach in the right posterior ray, /. e. 
a radial followed by three plates in the series, instead of two, 
as in the other four rays. This appearance is caused by the 
fact that the two lower plates in the ray are the representa- 
tives of a compound radial, transversely divided, the lower 
half being a radianal, located in its primitive position as 
infer-radial, resting upon the basals and directly under the 
super-radial. This is clearly demonstrated by eleven speci- 
mens in my possession showing the right posterior ray, all 
of which exhibit this structure. Goldfuss' figure (Petref. 
Germ., Taf. 58, fig. A,) which was copied by Pictet, does not 
show it ; but Ouenstedt, who also copied Goldfuss' figure A, 
gives an original figure of the posterior side of another spec- 
imen from Dudley, in which the extra plate in the right pos- 
terior ray is perfectly plain (Handb. d. Petref., Taf. 75, 
fig. 1 1 j . It appears in the figure on the left side ; but it must 
be remembered that the figure is reversed, so that what is 
really the right posterior ray appears as if it were the left. 
The condition thus presented is precisely that of the in- 
adunate genus Dciidrocrinns ; and we find that there is in 
