130 
MONOGRAPH OF THE GENUS STROPHIA. 
dish, but more prominently on the smaller whirls. The outer margin 
is white, but within, there being an abrupt line of demarkation, it 
is dark purplish brown. 
DIMENSIONS. 
Size of type, 1.20 by .42. Largest specimen, 1.22 by .45; smallest, 
1.18 by .40. Greatest diameter. .45; smallest, .40. Largest specimen, 
1.22: smallest, 1.18. 
OBSERVATIONS. 
Specimens do not vary essentially from the type. This is a re- 
markable shell. In it we find the maximum number of striations, no 
other known species having so many. It may be considered the type of 
a group of Strophias having the peculiar channeled, greatly elongated 
tooth. These, as far as my present knowledge extends, are confined to 
the island of Inagua, where all of the species of Strophia are thus char- 
acterized. 
By the teeth alone, the Strophias may be divided into at least 
four sharply defined groups, as follows:- 
LoWER TOOTH, GREATLY ELONGATED, CHANNELED; POSITION, CENTRAL. 
Lower tooth, projected backward along the lower wall, at least be- 
yond the first whirl and channeled excepting on upper termination. 
(See Eig. 32, a, where is given the upper termination of the chan- 
neled tooth of S. dallii; o, being the tooth and c, the frontal bar; e is the 
upper termination greatly enlarged, showing beginning of channel. At 
Fig. 33, A, is the lower termination of the tooth of S, pallida.) Habi- 
itat of species, Inagua, Bahamas. Type, S. dallii. 
Lower tooth, elongated, simple; position, central. 
Lower tooth, projected back into the aperture for a distance at 
least four times its height, but it is not channeled, being a simple py- 
ramid. ( See Plate II, lc, where a side view of the elongated central 
tooth of S. pannosa is given; in Fig. 33, a top view of the same is repre- 
sented; at ib. c, is given the top of that of S. copia; the top of that of S. 
nana is figured at ib. i.) Habitat of species, the Cayman Islands. 
Type, S. pannosa. 
Lower tooth, short; simple; position, central. 
Lower tooth, short, its length being no more than three times its 
height, and its position is about central. ( See Plate VII, 17b, where 
