156 ANTHURDXE. 



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, setae, 

 of which the extremity, along the inner edge, is finely 

 retro-serrated. We regard this pair of organs as the 

 second pair of maxillae, very similar in general structure 

 to those of the genus &ga and its allies. We have found 

 no trace of the first pair of maxillae, 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, Mga> &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 * levre inferieure' 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 Par. Costana has been applied by Prof. 

 Westwood. 



