SHUMARD—CRETACEOUS FOSSILS. 591 
GENUS AMMONITES. 
A. INEQUIPLICATUS, hi. sp. 
Shell large, gibbous, sides rounded ; dorsum flat or very 
slightly convex ; volutions four, partially embracing; umbili- 
cus deep, less than the width of the last volution, exhibiting 
about one half of each of the inner coils ; aperture transverse, 
subreniform ; surface of body volution ornamented with from 
25-28 very prominent, unequal, rounded coste, some arising 
tinued over the dorsum, at the margins of which they become 
obtusely angulated. Each rib bears two moderately distinct 
es, which are situated at their dorsal angles. In mature 
be, which is marked with several small points; superior 
lateral lobe oblique, its extremity furnished with four slender 
branches, each bearing several small points. : 
Diameter 5 inches, width of last volution 2 inches, thick- 
cies. It was found near the base of our Cretaceous strata, In 
Septariee, embedded in blue marly clay at Garnet's Bluff, on 
- d River, Fannin county, associated with Ammonites Swal- 
a and 4, Meekianus. Collected by Dr. G. G. Shu- 
A. SWALLovII, n. sp. 
a Shell compressed, discoid; sides gently convex; dorsum 
Attened, transversely ribbed, nodose-bicarinate ; volutions 
ont, partially embracing; umbilicus deep, exhibiting about 
out as wide 
rs one half of the width o* the last volution; aperture subo- 
bigs longer than wide, truncated and narrowest at the ve 
t €; surface marked near the umbilicus with a series oj 
“ansversely elongated nodes or tubercles, from each of whic 
33 ; 
