156 ANTHURIDA. 
The mouth, of which the peculiar structure has been 
overlooked by all previous writers, is evidently formed 
for suction, and consists of a narrow process extending 
along the anterior half of the under side of the head, 
and porrected in a point in front.* 
The mouth is closed beneath by a pair of foot-jaws, 
each composed of two oblong, flattened joints, the 
second of which is slightly curved and somewhat pointed 
to the tip, and armed along its inner edge with a series 
of long hairs. Within this pair of foot-jaws appear 
two long and extremely slender, nearly straight, sete, 
of which the extremity, along the inner edge, is finely 
retro-serrated. We regard this pair of organs as the 
second pair of maxilla, very similar in general structure 
to those of the genus 4Zga and its allies. We have found 
no trace of the first pair of maxilla, but the mandibles 
appear to be represented by a pair of elongated, pointed 
organs, having a three-jointed palpus, bearing a close 
general resemblance to the mandibles and their appen- 
dages in Limnoria, Aiga, &c. These organs rest within 
or beneath an elongated, conical, horny piece, of which 
the tip appears to be deeply bi-sinuated, forming the 
upper lip, and within the mouth we find another elon- 
gated, single organ, thickened at the base, which may 
possibly represent the ‘ lévre inférieure’ of Savigny. 
The seven following segments of the body are quite 
distinct, the anterior ones being the longest, whilst the 
last, or seventh, is the shortest of them all. The incu- 
batory pouch in the females extends from the second 
to the seventh segment. 
The tail is composed of six segments, the four an- 
* . . . . . . . . 
This description is made from individuals of the second species, above 
alluded to, to which the name of Pur. Costana has been applied by Prof. 
Westwood, 
