260 
NODTDS: 
Nore on tHE Nepronic Snett or Mexo Inprcvs, Guet. (Read 
14th November, 1902.)—The embryo shells extracted from the egg-cluster 
of Melo Indicus, Gmel., exhibited to-night by Mr. Fulton, show one 
extremely interesting feature. In most gastropod shells the apical whorls 
(protoconch, or nucleus) are distinctly marked off from the succeeding 
whorls by a well-defined line, and whilst either plain or having a sculpturing 
of their own differ in any case in ornamentation from the later or adult shell. 
It has generally been held that this line of demarcation, indicative of 
a pause in the growth of the shell, also showed the extent of the growth 
of the shell within the egg, the deposition of shell bearing the markings 
of the adult not taking place until after exclusion from the egg. 
In the present instance, however, every one of the young, or nepionic 
shells, extracted from the egg- capsules has begun to form shell having the 
colour- -markings of the adult, so that in this case the pause in growth, 
which, moreover, is but faintly marked, if at all, affords no measure of 
the extent of the shell formed within the egg, shell formation having 
been resumed on the adult plan prior to exclusion. 
It would be a matter of great interest to learn if other similar instances 
occur, or whether the present is an exceptional example. 
B. B. Woopwarp. 
Note on A Mownsrrostry oF Rrssora parva, Da Costa. (Read 
12th December, 1902.)—In a haul of the dredge taken in from 5 to 10 fathoms 
off the north of Guernsey last Summer there occurred a large number 
of Rissoia parva, including specimens of the usual colour and of the 
var. nigra, Norman. 
Monstrosity of Rissoia parva, Da C. 
One specimen of a distorted form was taken in which the earlier whorls 
are quite regular, but suddenly—owing probably to an injury to the 
animal—the shape is entirely altered and the sculpture ceases, the shell 
becoming smooth. The whorl is flattened vertically, being squeezed out, 
and a large broad carination appears. The specimen was alive, but 
immature, ‘and, unfortunately, was not detected until the animal was dead. 
E. R. SyKEs. 
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