Casey — Notes on the Plewrotomidae. 169 
being the very broad shallow anal sinus situated on the peri- 
phery and not on or near the suture, which is its invariable 
position in the Daphnellini. The only genus at present 
known is Taranis Jeffr., a very minute and fragile shell, with 
the aperture broadly oval and the canal very short. The 
surface is clathrated by equal longitudinal and spiral raised 
lines and is without trace of true ribs. The body whorls are 
about three in number. No extinct species of Taranis is 
known from the European strata, but, singularly enough, a 
species which, from the figure, appears to be a true Taranis, 
was described by Prof. Harris from'the middle Eocene strata 
of Smithville, Texas, under the name finexa (Proc. Ac. Nat. 
Sci., Phila., 1895, p. 64). This is one of the most interest- 
ing discoveries yet announced among our extinct Gastropods. 
MIrroMORPHINI. 
The species of this tribe are very small, oval or fusiform in 
outline and generally strongly, spirally sculptured. The aper- 
ture is long and more or less narrowly oval, and, owing to the 
fact that the anal sinus is obsolete, some doubt exists as to 
their true relationship. In placing the tribe provisionally with 
the Pleurotomidae I merely follow the usual custom, having 
made no determinative studies myself. The species seem to 
be few in number and individually rare or, at least, but few 
exist in any collection accessible to me at present. The only 
representative in my cabinet has the apex of the shell worn 
away so that I am unable to describe the embryo, except in 
general terms as shown in the West Indian fossil forms de- 
scribed by Dr. Dall, in which it appears to be small, rounded 
or obtuse and paucispiral. 
Species of Mitromorpha have been described from Japan, 
California, the Pliocene strata of Florida and the European 
Pliocene, the latter, the subulata of Cossmann, apparently 
being a typical member of the genus; so its distribution, 
though limited to the northern temperate regions as far as 
known, is, or has been, very extended. The columella is 
sometimes bi- or triplicate at the middle, and the outer lip is, 
