26 PSEUDOCERATITES OF THE CRETACEOUS. 
with this genus. The living chamber is short, the aperture has a blunt 
rostrum, there are shallow sinuses on the edges of the venter, a broad 
lateral rostrum on either side, and shallow sinuses between these and the 
umbilical shoulders, and probably a crest on the dorsum. 
The ventral lobe is very broad and short, with a broad short siphonal 
saddle. There are three bifid lateral saddles, with an incomplete apparently 
entire saddle at the line of involution. The lobes are short and much 
narrower than the saddles, and the entire outlines of both lobes and saddles 
have short obtuse marginal saddles and narrow, short, pointed, simple 
marginal lobes. 
The species is known to me only through Steinmann’s figures, which 
are reproduced on PI. I, figs. 1-3, with the single exception of his enlarged 
drawing of the side view of fig. 1. 
Locality: Pariatambo, Peru. 
Age: Albian (?). 
BUCHICERATID Hyatt. 
It has been found impracticable to unite the genus Buchiceras with any 
known family, on account of its peculiar development and sutures. The 
approximation to the Hystatoceratidz is close, so far as the earlier stages 
are concerned, the compressed, comparatively smooth-keeled young in the 
neanic stage having considerable resemblance, but these similarities are lost 
in the subsequent development, owing to the partial suppression of the costee 
and the very distinct sutures. The development and sutures separate these 
forms completely from Anemiceras. hey are separable from Tissotiidee by 
their first lateral saddles and their ventral lobes, and from Barroisiceras, 
which they also resemble, by the absence at all stages of a third line of 
tubercles and by their sutures. 
The‘sutures are similar to those of the discoidal smooth shell of uncer- 
tain affinities described as Mojsisovicsia by Steinmann. 
So far as known there are no representatives of this genus except in 
South America. It should be remembered, however, that all information 
heretofore published has come from this single fossil. 
The second genus included in this family, Roemeroceras, has similar 
ventral lobes and siphonal saddles, and the young, although quite distinct 
in being less compressed in the early stages, acquire a similar keel at a 
later age, and similar form and ornaments. 
