C. Spence Bate on the Pencidea. (4 
as it exists in some species in the female and not in the 
male. 
Penceus monoceros, Fabricius. 
(PI. XI. fie. 2.) 
Rostrum straight and ciliated on the lower margin; from 
the pomt the crest is a little elevated posteriorly, and 
armed with nine teeth, of which the posterior is a little more 
distant than the rest, and situated near the centre of the 
stomachicregion. The terminal flagella of the first pair of an- 
tenne are short, being less long than the last two joints of 
the peduncle. Legs short; and there are no spines on the 
margins of the telson. 
Length about 3 inches. 
Inhabits the coasts of India. 
The typical specimen is labelled from Bombay. It is a 
female, and offers no decided character in the arrangement of 
the posterior ventral plates of the pereion, from which I pre- 
sume that it is not a fully adult-formed specimen. Dana 
figures the cephalon of a specimen from Singapore (?) about 5 
inches in length; but it appears to differ little, in the parts 
that he has figured, from his own species P. velutinus, ex- 
cepting that in the latter the rostrum is pointed a little upwards 
instead of horizontally straight as in the type of P. monoceros, 
which differs from the specimen above described only in having 
a few spines on each side of the telson. 
Peneus indicus, M.-Kdw. (Pl. XII. fig. 5.) 
The rostrum is described by the author as being straight, 
styliform at the extremity, reaching beyond the distal ex- 
tremity of the peduncle of the first pair of antenne, and 
surmounted posteriorly by a crest which continues nearly to 
the third part of the carapace. Hight or nine teeth surmount 
the dorsal margin; and four or five are situated on the lower. 
The flagella of the first pair of antenne are slender and are a 
little longer than the peduncle of the same. In general cha- 
racters this description resembles P. setiferus. 
Length about 6 inches. 
It inhabits the coast of Coromandel. 
The typical specimen is labelled from the coast of Coro- 
mandel, and is a female. It is described as having the “ rostre 
droit,’ whereas the specimen has the extremity of the rostrum 
slightly elevated. In all other parts the description faithfully 
agrees with the specimen. 
So closely does this species coincide with the figure given 
by Heller of his P. tahttensis (‘ Reise der Fregatte Novara,’ 
