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carinated race, also a longitudinally ribbed race and one 
with obsolete or nearly obsolete longitudinal ribs.. The 
size and form of the embryoniec tip differs (according to 
the nutrition of the embryo in the ovicapsule) in different 
specimens of the same species. In one specimen it may be 
twice as large as in the next specimen and varies in the 
relative dimensions of its cone. T'he operculum is in this 
genus extremely variable and often absent entirely. Ofa 
peck of B. cyaneum var. Mörchianum (wich is the dwarf 
race of cyaneum with developed carinae and obsolete longi- 
tudinal ribs) five percent had no operculum and in many 
of these even the opercular gland was absent. In the larger 
species it is somewhat more constant, but the situation 
of the nucleus, in a five gallon keg of B, hydrophanum 
Hancock was from quite central to nearly on one edge, 
the form from olive shaped to quadrangular and frequently 
nearly circular. Of this keg of 200 or 300 specimens there 
were only seven males; all dwarfs. 
There is also another character which varies with the 
sex, that is, the roundness or flatness of the top of the 
whorls and by consequence the slope or turreted character 
of the spire. The large eggmass requires a greater capacity 
than the (also disproportionately large) penis of the male, 
consequently the female shells are always more rounded 
than the males even when of the same size and, if the 
refleeted lip be formed at the gravid period, it will be 
wider and more broadly reflected behind, than in a male 
or in a female-who has discharged her eggs before forming 
the reflected ip. 
Of other characters the epidermis may vary also with 
other features from velvetty and ciliated, to glossy and 
smooth in the same species, It will usually in quite per- 
fect specimens of the carinated races be found to be fringed 
or prolonged on the edge of the carinae. B. ciliatum Fabr. 
offers excellent examples of this. 
