458 ALE. Verril-— Catalogue of Marine Mollusca. 
turricula, Fig, 621, intended for B. harpularia; and Fig. 624, for 
B. cancellata, do not represent those species. Fig. 620 represent 2. 
harpularia better than “ B. turricula,’ for which it was intended. 
Fig, 624, badly represents some unrecognizable species, very unlike 
the one intended. 
Each species of the genus seems to have a longer and a shorter 
form, which often differ decidedly in appearance. This variation, 
which is also seen in many other genera of spiral shells, is probably, 
to a certain extent, sexual ;* but it is not entirely so, for while the 
males seem usually to be long-spired, with narrower and _ flatter 
whorls, I have also found males among the short-spired ones. 
Moreover, there are, evidently, geographical races or varieties, as 
well as irregular individual variations, and peculiarities due to inju- 
ries of various kinds. 
Unfortunately, writers have, hitherto, almost invariably neglected 
to state the sexes of shells figured or described; and, until recently, 
they have very seldom endeavored to give any idea of the character 
of the upper whorls, or of the young shell. In many cases it is dif- 
ficult, or even impossible, to ascertain, at once, the nature of the 
apical whorls of species of Bela, owing to the fact that a very large 
proportion of the specimens are nearly always badly eroded. But 
this difficulty can usually be overcome by collecting large numbers 
of specimens,t including series of the young. The upper whorls and 
apex of these and other shells often give more reliable characters 
than the later whorls. The neglect to ascertain the sex cannot be 
avoided, so long as conchologists mostly prefer to dry all their shells, 
* As the oviducts in many gastropods, which form large egg-capsules, are very 
voluminous and have large glands, which are situated beneath the upper part of the 
whorls, we should expect that this part of the mantle, and therefore of the shell, 
would be more expanded, to accommodate these organs. This seems to be the case, 
ordinarily. In examining large numbers of examples of Natica, Lunatia heros, Nep- 
tunea Stimpsoni, N. decemcostata Sycotypus canaliculatus, S. caricus, Buccinum unda- 
iwm, ete., with reference to their sexual characters, I have found that the females, as 
a rule, are decidedly stouter, with the whorls more convex, or at least more swollen 
just below the suture, than the average males. But the difference is often not very 
marked, while each sex varies considerably in this respect, from other causes. 
+ Although I have made special efforts to collect and preserve as many specimens 
ot Bela as possible, while engaged in dredging on our coast, nearly every season, dur- 
ing the past twenty years, I am free to confess that I have not yet been able to obtain 
a satisfactory series of all our species. For this and other reasons, this paper is not, 
so far as this genus is concerned, to be regarded as complete, for our species, but 
only as preliminary to a more complete and more fully illustrated one. 
eS ee 
