REPORT ON THE CRUSTACEA MACRURA. 



721 



Habitat. — Pacific. Taken at the surface, associated with Hectarthropus compressus, 

 on the passage from A pi, New Hebrides, to Cape York. 



The animal is broad, short and stout, and free from ornamentation on the carapace 

 and pleon. The carapace is nearly as deep as the length between the orbital and posterior 

 margins, it is anteriorly produced to a short rostrum (fig. 2c) that is laterally com- 

 pressed and pointed at the apex, and only feebly serrate, if at all. The orbit is broadly 

 excavate, and has the outer canthus armed with a long, straight tooth, the extremity 

 of which is curved into a well-formed hook (fig. 2c"). whence the frontal margin is 

 excavate to receive the second antennae, the fronto-lateral angle being produced to a 

 strong tooth. 



The pleon is smooth, and all the somites are short ; the third, which is the longest, is 

 arcuate dorsally near the centre, and the fourth somite articulates with it at a right angle 

 to the anterior somites ; the sixth somite is a little longer than the fifth, and the telson 

 is a little longer than the sixth, and tapers to the distal extremity. 



The ophthalmopoda are short and pyriform, the ophthalmus being orbicular, and not 

 reaching as far as the extremity of the rostrum. 



The first pair of antennas is short, the peduncle reaching scarcely beyond the 

 ophthalmopod, and not as far as the apex of the rostrum, and it terminates in two 

 rudimentary flagella. 



The second pair of antennae has the basal joints very short and thick ; the scapho- 

 cerite is subequal in length with the first pair, and the flagellum is broken off a little 

 beyond the peduncle. 



The first two pairs of pereiopoda are all short and chelate (fig. 2k) ; the others are 

 short and simple, the posterior pair being a little longer than the preceding; they 

 carry no basecphysis, but in each, attached to the membranous articulation of the coxal 

 joint with the pereion, there is a small arthrobranchial plume. 



The pleopoda are short and biramose. The posterior pair, which forms part of the 

 rhipidura, is foliaceous and as long as the telson, which tapers to the posterior margin, 

 which is fringed with hairs. 



(ZOOL. CHALL. EXP. PART LII. — 1887.) 



Fff 91 



