MONOGRAPH OF THE GENUS STROPHIA. 
181 
is given a side view of the short tooth of S. alba, and Fig. 33, b, where 
is represented the top of the tooth of S. neglecta.) Habitat of species, 
Bahamas. — excepting Inagua — Cuba, and probably Hayti. Type, S. 
neglecta. 
Lower tooth, short; simple; position, not central. 
Lower tooth, very short, its length being no more than twice its 
height, but its position is considerably to the right of the center, being, 
in fact, placed nearly on the column. ( See Fig. 34, a, where is given 
an enlarged cut of the teeth, lower and upper, of S. uva, showing the 
near proximity of the two, and the position of the lower, almost on the 
column.) X cannot at present clearly define the habitat of the species of 
this group. It is, however, safe to say that they are found on the more 
northern of the Windward Islands, and some of the keys off the north 
coast of South America — Curacoa and vicinity. Type, S. uva. 
[Note. The material examined upon which the foregoing conclu- 
sions are based, consists of at least three fourths of the known species 
of Strophia. Of course among the large amount of fresh material to be 
gathered, for without doubt, nearly every island among the Bahamas 
and other West Indies, not yet explored for Strophias, will yield one or 
more species, forms may occur that will, perhaps, cause me to modify 
my ideas somewhat, but I have considered it best to give this exposition 
of my studies upon the group up to date, in order that students may 
better understand my descriptions. Further remarks upon this head 
will be given under General Conclusions.] 
An understanding of these groups, as defined, is of great impor- 
tance in determining species in Strophia. Of course, other characters 
are often constantly found in a given group. For example, the Inagua 
Srophias, having the channeled tooth, are nearly alw r ays cylindrical, the 
the first three whirls being about equal in diameter, while the striations 
are fine and numerous. Both of these characters are also found in the 
short toothed group, but here they are not constant, nor do they always 
occur together. Other groups possess other characters, to be mentioned 
elsewhere. In fact, it is nearly always possible to find species in one 
group that bear a superficial resemblance to others in different groups, 
when they are really utterly different. 
The sharply defined difference in the teeth, as pointed out, becomes 
of more importance wdien we consider that specific characters are much 
less prominent in Strophia than in many other genera of shells, al- 
though as constant as those more easily perceived. Thus these groups 
become, in a measure, sub- generic. 
