WHITE.] CRETACEOUS FOSSILS. 21 
species: Anomia propatoris, Corbicula carletoni, Melampus? antiquus, 
Neritina bannisteri, Neritina (Velatella) bellatula, N. (V.) carditoides, 
Turritella spironema, Hulimella? inconspicua, H.? chrysallis, and Val- 
vata nana. The fauna also contains another Turritella, a Unio, and two 
or three other undetermined species. For Mr. Meek’s remarks upon this 
fauna see the Annual Report of this Survey for 1872, pp. 442-445. 
Peculiar interest attaches to this estuary fauna in different ways, but 
especially. because some of its species indicate the existence of types at 
that early period which are found to characterize the fossil molluscan 
faunze of later epochs as represented by North American strata; and of 
some that are also common among living North American forms. Espe- 
cial reference is had in this remark to the fresh-water and land mollusca. 
The strata containing the fossil fauna in question were evidently deposi- 
ted in the estuary of a stream, which, during at least a portion of the 
Cretaceous period, flowed into the sea from the narrow continental region 
of Mesozoic time, the eastern shore of which was evidently near that local- 
ity. There were doubtless other similar estuaries along that and other 
shores of the Cretaceous seas, but little is yet actually known of them. 
Unfortunately, also, the excavations which exposed the strata bearing 
the fauna in question, at Coalville, have been discontinued and covered. 
with débris, and none of its species have yet been found elsewhere. Our 
present knowledge of this deposit is therefore confined to that one 
limited locality. 
Genus PHARELLA Gray. 
PHARELLA? PEALEI Meek. 
‘Plate 11, figs. 6 a and 6 b. 
Pharella? pealei Meek, 1873, An. Rep. U. 8. Geol. Sur. Terr. for 1872, p. 496. 
No other than the type specimens of this species have ever been dis- 
covered; the best one of which, although only a cast, is figured on plate 
11. The following is Mr. Meek’s description of it: 
“Shell elongate or subrhombic, the length being about twice and a half 
the height, rather compressed; anterior margin slightly sinuous just in 
advance of the beaks above, and somewhat narrowly rounded below this 
faint sinuosity ; posterior margin truncated, with a convex outline, very 
obliquely downward and backward from the posterior extremity of the 
hinge to the prominent and very narrowly-rounded or angular posterior 
basal extremity; hinge-line proper, apparently comparatively short, and 
not forming any angularity of outline at its connection with the sloping 
posterior dorsal margin; beaks rising a little above the hinge margin, 
but rather depressed and placed about one-fifth the entire length of the 
valves from the anterior margin; basal margin long, slightly sinuous 
along most of its length; posterior dorsal slopes rather prominently 
rounded from the beaks obliquely to the posterior basal extremity. 
Surface only showing obscure lines of growth. 
“Length, 1.20 inches; height, 0.48 inch; convexity, 0.28 inch. 
* Knowing nothing of the hinge of this shell I only referit provisionally 
to Pharella. it doesnot seem to have had the extremities gaping as in that 
genus, but the specimen has evidently been accidentally compressed, and 
this may have given the valves the appearance of being closed. In gen- 
eral appearance it resembles Solen guerangeri @Orbigny, which seems to 
belong to the genus Pharella. Our shell, however, evidently differs from 
dOrbigny’s specifically, at least, in not having the posterior margins of 
