150 Records of the Indian Museum. [VOL. 
while differing as regards details of classification, agree in recog- 
nizing only the genus Scalpellum, which they subdivide in differ- 
ent ways. Gruvel’s classification (1905) was, indeed, based on 
that set forth by Hoek in the ‘‘ Challenger ’’ Reports (1883) ; but 
the latter author has recently published a new one in his account 
of the Cirripedia of the ‘‘ Siboga’’ (1907). 
Taking into consideration the great difference in external form 
between the males of such closely allied forms as Scalpellum squamu- 
liferumand 5. bengalense, and the variation displayed by the valves 
in certain species, notably S. squamuliferum and S. laccadivicum, 
I find it possible to recognize only two groups of species that can be 
called subgenera It is impossible to regard them as distinct genera, 
because no one character of importance can be stated to be con- 
stant in either of them, although the sum of the characters of each 
differs from that of the characters of the other. These two groups 
may be called Smalium and Scalpellum. The former is undoubt- 
edly the more primitive and includes several species that come very 
close to Pollicipes, while the latter consists of forms that have 
undergone a considerably greater amount of specialization. The 
two subgenera may be defined as follows :— 
SMILIUM, Gray. 
Rostrum and subcarina as a rule well developed in the herma- 
phrodite, but the subcarina sometimes absent; anal appendages 
usually with one joint, sometimes absent. Dwarf males with 
well-developed capitulum, cirri, mouth parts and alimentary canal. 
TyPE Smilium peronit, Gray. 
SCALPELLUM, Leach. 
Subcarina absent or represented by a mere rudiment ; rostrum 
often absent, never large or prominent ; anal appendages as a rule 
with several or many joints. Dwarf males with the appendages 
and alimentary canal degenerate and the capitulum not distinct 
from the peduncle. 
Typr Scalpellum vulgare, Leach (= Lepas scalpellum, Vinne). 
Both these subgenera are represented in Indian seas, Smilium 
by three species and Scalpellum by at least twelve. 
Subgenus SMILIUM. 
Key to the Indian spectes of the subgenus. 
I.  Capitulum of hermaphrodite about half 
as broad as long. 
A. Peduncular plates in the form of 
rods set obliquely in the mem- 
brane and forming complete 
circles round the peduncle .. S.squamuliferum. 
