1872.] . 21 (Hyatt 
erease of the single pile, which make their appearance between the 
bifureated pile. The latter do in old age entirely give way to the 
bifurcated, and in some adults are very numerous. It should be 
mentioned that Oppel found spines on the umbilical whorl of Sower- 
by’s original, and the Museum specimen described above has one or 
two fine spines on what is probably the eighth whorl. 
Dactylioceras Braunianum. 
Amm. Braunianus D’Orb., Terr. Jurass., Ceph., p. 327, pl. 104. 
Dactylioceras Braunianum Hyatt, Bull. Mus. Comp. Zoology, no. v, 
p- 95. 
The cast of this species is particularly interesting. At or just 
before the adult stage the cast does not receive any impression from 
the abdominal pile, and looks smooth, narrow and subangular. 
The pile are prominent laterally, and have very slight tubercles. 
That the pile are continued on the exterior of the abdomen until 
a much later period than this, is very probable. The young of this 
species has, after the smooth stage, a period with tuberculated pile, 
during which the shell closely resembles the adult of Celoceras cras- 
sum, having the same form and crenulations. Subsequently we see 
a repetition of the rounded sides of Dactylioceras commune, and as 
these flatten and the abdomen narrows, the whorls resemble those of 
Daciylioceras annulatum. 
Descriptions oF New Species or Marine MoLuusks FROM 
THE Coast or Fioripa. By Ropert E. C. STEARNS. 
Marginella (Glabella) opalina Stearns. 
Shell ovate, solid; light to dark amber, some specimens showing 
obscure bands, more or less intense, of same color; subtransparent, 
smooth, polished; spire elevated, apex rounded; whorls four, suture 
distinct; aperture rather more than half the length of the shell; outer 
lip thickened, internally crenated, and strongly notched above; colu- 
mella with four well developed plaits. 
Largest specimen measured long. .21, lat. .1 inch; 
Smallest do. don) lenge. 17, lat:’:09 inch. 
Habitat: Rocky Point, Tampa Bay, west coast of Florida, where 
several specimens were collected by Col. E. Jewett and myself; this 
beautiful little shell was found by us upon the under side of bunches of 
oyster shells, near low water mark. I know of no other species with 
which it might be confounded. 
