148 Records of the Indian Museum. [VOL. V, 
than is the case in the more primitive species. The mouth 
parts and anal appendages have completely disappeared and even 
the penis is absent; the alimentary canal is a mere rudiment, 
without mouth or anus. 
Such males are of course incapable of feeding, whereas those 
of Smilium apparently nourish themselves in the manner charac- 
teristic of the Cirripedia, that is to say by wafting minute living 
organisms to their mouth by means of the cirri and then either 
masticating them or swallowing them whole. 
Specific characters are less strongly marked in the case of the 
more degenerate males than they are in that of the males of Smz- 
lium, but the nature of the armature is often characteristic, and 
certain species (¢.g., S. velutinum) could almost be distinguished 
by an examination of their males alone, on account of peculiari- 
ties in the spines with which the males are invested. 
The exact shape of the more degenerate males is, however, a 
dangerous character on which to lay great stress in classification 
or specific diagnosis, for it is very liable to be distorted by pres- 
sure or by the methods of preservation commonly adopted. 
INDIVIDUAL VARIATION IN SCALPELLUM AS RE- 
GARDS THE DEVELOPMENT OF VALVES. 
A fact that has caused some confusion as regards the taxo- 
nomy of Scalpellum has recently been brought to light by the 
researches of Hoek and Pilsbry ; I mean the fact that in certain 
species certain hermaphrodites and females have the capitular 
valves incompletely developed, so that the valves appear as mere 
skeletons. Such individuals may conveniently be called ‘‘ incom- 
plete,’’ while more normal individuals may be called ‘‘ complete.” 
Incompleteness of the valves is usually accompanied by a thicken- 
ing of the membrane in which they are embedded and consists 
mainly in an excavation of one or more margins of the larger 
paired valves and of a reduction in the size of the latera and 
carina. 
Just as in Dichelaspis it is often possible to trace the outlines 
of the fine primitive valves of the Lepadide on the membrane 
of the capitulum even in species in which the valves themselves 
have almost disappeared as calcified plates, so in incomplete forms 
of Scalpellum the outlines of twelve or more large valves can be 
seen, with the calcified plates occupying only part of their area. 
The nature of the reduction, however, resembles that seen in 
Conchoderma rather than that found in Dichelaspis. It is per- 
haps noteworthy that the reduction of the valves in the dwarf 
males of Scalpellum is again of a different nature, an actual re- 
duction in number taking place, and that the valves in these de- 
generate individuals differ from those found in typical Lepadide 
in including a rostrum, a valve that is never found in that family. 
The six valves of the dwarf males of Smilium apparently represent 
the six essential valves of the genus Scalpellum, for there is a stage 
