WHITE.] CRETACEOUS FOSSILS. 25 
he gave to the genus. These varices are not present on the shell here 
discussed; but to my mind the narrow groove situated near the distal 
border of the volutions in both shells is of greater generic value than the 
varices. Of equal or greater generic value also is the reversed apex of 
our shell, which is evidently a constant characteristic; but it is not yet 
known whether the apex of the type of Rhytophorus is also reversed. 
Until this question can be decided I prefer to leave this species where 
Mr. Meek originally placed it, in the genus Melampus, although it is quite 
certain that it does not strictly belong there, rather than to formally 
transfer it to Rhytophorus, or to propose a new generic name. 
MELAMPUS ? ——? 
Plate 12, fig. 6a. 
M-lampus ——? Meek, 1873, An. Rep. U: 8. Geol. Sur. Terr. for 1872, p. 439. 
Mr. Meek obtained from the marine strata at Coalville a single exam- 
ple of a shell, which is evidently congeneric with the Melampus antiquus, 
from the estuary beds there, aud which has just been described. It is 
too imperfect to base a specific description upon; but it is probably dis- 
tinct from the last-deseribed species. Allits associates are marine forms, 
and if it is a littoral pulmonate Gasteropod, as it is supposed to be, it was 
probably drifted to its marine entombment from an adjacent shore, just 
as the Physa probably was, which was found in the same or associated 
strata, and which is figured on plate 7, fig. 13, of Contributions to Inver- 
tebrate Paleontology No. 1,in the annual report of this survey for 1877. 
The character of the specimen here referred to Melampus is well shown 
by fig. 6 a, plate 12, but it is thought best to wait for better examples 
before giving it a specific name. 
Genus NERITINA Lamarck. 
NERITINA BANNISTERI Meek. 
Plate 12, figs. 10 a, b, and e. 
Neritina (Neritella) bannisteri, Meck, 1873, An. Rep. U. S. Geol. Sur. Terr. for 1872, 
p. 499. 
This species is one of the estuary Cretaceous fauna before referred to, 
which was discovered by Mr. Meek, at Coalville, Utah. The figures of it 
on plate 12 have been drawn from one of Mr. Meek’s types, and the follow- 
ing is his description of the species, together with his remarks upon the 
same : 
“Shell, subglobose; spire much depressed, or with its apex scarcely 
rising above the body-whorl; volutions three or four, rapidly increas- 
ing in size, so that the last one comprises neariy the entire shell, more 
or less flattened, and sometimes provided with an obscure linear revolv- 
ing furrow above; aperture large, subovate, approaching semicircular, 
being a little straighter on the inner side; outer lip beveled to a thin 
edge; inner lip of moderate breadth, slightly concave, and flattened, 
with asteep inward slope, entirely smooth. Surface polished, and marked 
by crowded zigzag vertical bands of brown and light-yellowish colors ; 
lines of growth moderately distinct. 
“ Height of a nearly medium-sized specimen 0.40 inch; breadth, 0.43 
inch. Some examples are as much as twice these dimensions. 
