214 PSEUDOCERATITES OF THE CRETACEOUS. 
Until a late age this shell is separable from stantoni or pseudoplacenta 
by the presence of the minute median lateral line of tubercles. The larger 
size and wider separation of the ventral tubercles separate the younger 
stages, in which the venter is often very narrow and the sutures similar to 
those of whitfieldi, from var. tuberculatum of that species. The sutures, 
however, as a rule, have less complex outlines and more solid-bodied saddles 
and less concave septa, as stated above. 
Locality: New Jersey, Alabama. 
Age: Matawan formation (clay marls), Upper Cretaceous. 
PLACENTICERAS STANTONI n. sp. Hyatt. 
Placenticeras placenta Stanton (pars.), 1894, Bull. U. 5. Ceol. Survey No. 106, pl. 39, 
figs. 2,3, not fig 1. 
Locality: Upper Kanab Valley, Utah. 
Age: Colorado epoch, Upper Cretaceous. 
PLACENTICERAS STANTONI variety BOLLI Hyatt. 
Pl. XL, figs. 3-7; Pl. XLI; Pl. XLII; Pl. XLIII, figs. 1, 2. 
Placenticeras intercalare Meek (pars.), 1876, Mon. U. 8. Geol. Surv. Terr., Vol. 1X, 
p- 471. 
This species is very like P. placenta and whitfieldi, but has much stouter 
volutions with broader venters at the same age and is intermediate in 
character between intercalare and whitfieldi. The costee are of the syrtale 
type, but are merely obscure folds on these casts. The tubercles are sparse 
and on the umbilical shoulders as in placenta. ‘The costz are occasionally 
bifid on the outer part of the side with single ones between them. The 
elongated ventral tubercles are alternate and each one has its costation. 
The sutures have much shorter lobes and stouter, shorter saddles than in 
placenta. 
The young in the nepionic stage have a smooth volution with rounded 
venter. Inthe neanic stage this changes through the elevation of the venter. 
The ventral zone is at first quite broad comparatively and perfectly flat in 
the neanic stage. In the ephebic stage it becomes much narrower and con- 
cave and probably then acquires its tubercles. The tubercles on the 
umbilical shoulders do not appear until this stage begins. 
