ENGONOCERATID &. LETS) 
NEOLOBITES PERONI n. sp. Hyatt. 
Neolobites vibrayeanus Peron, 1890, Moll. Crét. de la Tunisie, pl. 18, figs. 1, 2 
A highly compressed shell with narrow flat venter bordered on either 
side by a line of small, closely set tubercles with numerous cost on the 
flat sides, focussed into a very few large nodes near the umbilical shoulder. 
The involution is almost if not quite complete. The umbilicus is not 
figured in Peron’s figure, but it must have been very small. In extreme 
age these nodes recede farther from their first position, the ventro-lateral 
lines of small tubercles disappear and the venter becomes elevated and is 
represented in the last stage as subacute. ‘There are five or six lateral saddles 
in this species, according to Peron’s drawing. Peron considered this 
form to be distinct, but did not describe it as a new species. 
Locality: North Africa. 
Age: Cenomanian. 
METENGONOCERAS n. gen. Hyatt. 
The shell is compressed as in Engonoceras and the involution covers 
the greater part of the sides of the internal volutions. Broad, fold-like 
sigmoidal costz are present in some species and faint tubercles have been 
observed in rare cases on casts. No well-preserved shells have been so. far 
seen nor described. The venter in the neanic stage is comparatively broad 
and slightly concave; in the ephebic stage it becomes very narrow, but 
retains a linear concavity; in the full ephebic stage it becomes acute, and 
in gerontic stage subacute and then rounded. The sutures do not differ 
materially from those of Hngonoceras; the distinction, so far as known, lies 
in the development of the venter and absence of nodes. The young were 
similar to the adults of Protengonoceras, as are those of other genera. The 
principal or outer lateral lobes and saddles are short, the lobes narrow and 
entire between the entire and more or less rounded, often phylliform bases 
of the principal saddles. The apical ends of the lobes are denticulated, but 
the marginals are entire, pointed, and the saddles blunter but also entire. 
The smaller inside of the principal outer saddles are often bifid. The 
ventral lobe is narrow orally, very short and broad apically, with two 
entire arms, and is divided by a depressed but more or less subacute entire 
siphonal saddle. he first lateral saddles in most species are broad and 
