ORTMANN : TERTIARY INVERTEBRATES. 
169 
Miocene of Virginia, which differs, however, in the more strongly angu- 
lated periphery, flatter whorls and coarser threads, and C. metrium Dali 
(p. 394, pi. 22, f. 27) from the older Miocene of Florida, which differs in 
the flat whorls and the finer sculpture. 
10 1. Calliostoma iheringi Ortmann. 
PI. XXXI, Fig. 7“’ 6 . 
1900 C. i. Ortmann, in: Amer. Journ. Sci., v. 10, p. 373. 
Shell conical, broader than high, scalariform, umbilicated. Six whorls, 
which are sharply angulated ; one angulation is formed by a sharp revolv- 
ing keel in the upper part of the whorls, a second one — exposed only on 
the last whorl — is formed by a keel on the periphery. Suture distinct, 
forming an obtuse angle; upper part of whorls (above upper keel) oblique, 
flat, with 5 to 6 revolving threads, which are slightly granulated ; lower 
part (below that keel) vertical, slightly concave on the last whorl, with 5 
to 7 fine, smooth threads. Base of shell slightly convex, depressed toward 
the umbilicus, which is moderately large. About 18 revolving threads on 
the base, which are smooth, more crowded and finer toward the periphery, 
a little stronger near the umbilicus, where the intervals are about as broad 
as the threads. 
Height, 9.5 mm; diameter, 12 mm. 
Remarks: The presence of an umbilicus brings this species into the 
subgenus Eutrochus. 
Record of specimens : Mouth of Santa Cruz River, 1 sp. 
Affinities: A species that resembles this one in the presence of two 
angulations on the last whorl, and belongs also to the subgenus Eutrochus 
is: C. cyclus Dali (1892, p. 403, pi. 23, f. 20) from the Miocene of North 
Carolina, but this one is much lower. Another species with the same 
double angulation and open umbilicus is Trochus biangulatus Eichw. (see : 
Hoernes, 1856, p. 460, pi. 45, f. 5) from the Miocene of Europe, but it is 
much higher. The latter species is said to be identical with T. ditropis 
Wood (1848, p. 133, pi. 14, f. 9) from the Pliocene of England. The 
latter, however, in external form, is more like our Patagonian fossil, being 
less high than the Miocene form, and it differs from C. iheringi in the 
upper angulations being more prominent, the number of revolving threads 
being different, especially on the base, which is said to be finely imbricated. 
