Exploration of the Red River of Louisiana, in the year 1852 / by Randolph B. Marcy ; assisted by George B. McClellan. Page: 196 of 368

                                
180

APPENDIX E.-PALiEONTOLOGY.

ribs four or five, longitudinal, irregular, rounded, nodulose; surface
marked with concentric imbricating lamellae; superior valve rather thin,
ovate, nearly plane, slightly convex near the peak, surface with four or
five well marked longitudinal undulating sulci.
It occurs at Fort Washita with Gryphcea Pitcheri and Ammonites
vespertinus. It appears to be quite rare, the specimen figured being the
only one furnished by the expedition.
INOCERAMUS CONFERTIM-ANNULATUS, Roemer.
PALEONTOLOGY, Plate 6, fig. 2.
Inoceramus confertim-annulatus, F. Roemer, Texas, 402. Kreidebild.
Texas, 59, taf. vii, fig. 4.
Shell ovate, depressed with close concentric undulating ribs; ribs
prominent, rounded, regular, intervals about equal to width of ribs.
I refer this fossil to the above species with some hesitation, as all the
specimens of the collection are either weather-worn or badly mutilated.
Nevertheless, if not identical, ours is a closely allied species. Occurs
rather abundantly at Camp No. 4, Cross-Timbers, Texas. Dr. F. Roemer's
specimens are from the Guadalupe, near New Braunfels.
TRIGONIA CRENULATA, Lamarck.
PALEONTOLOGY, P1. 4, fig. 1.
Trigonia crenulata, Roemer, Kreidebild. Texas, 51, taf. vii, fig. 6.
Shell trigonal, thick, with from fourteen to fifteen oblique crenulated
ribs in each valve; anterior side wide, rounded, inflated; posterior side
produced, compressed; inferior margin rounded.
From Cross-Timbers, Texas. All the examples in the collection are
internal casts. Roemer cites this species from New Braunfels.
ASTARTE WASHITENSIS, Shumard.
PAL.aONTOLOGY, Pl. 3, fig. 3.
Shell ovate, trigonal, a little longer than wide, compressed, inequilateral,
marked with fine concentric rounded strie; buccal side shorter
than the anal, excavated; basal margin rounded, truncated posteriorly,
beaks slightly prominent, excavated.