REPORT ON THE CRUSTACEA MACRURA. 649 



teeth extends to the posterior limit of the gastric region ; the rest of the carapace is 

 smooth, with a polished surface. The anterior or frontal margin carries a long antennal 

 tooth, and the rudiment of one at the fronto-lateral angle. 



The pleon is smooth and free from armature ; it is laterally compressed, especially 

 behind the third somite. In the third the compression is dorsally increased, so as to 

 produce a small carina, that disappears both at the anterior and posterior extremities of 

 the somite. The telson is laterally compressed, armed at the dorsolateral angles with 

 three small spines, and terminates in a few small hairs. 



The ophthalmus is large and reniform, black in colour, and stands upon a short 

 ophthalmopod. 



The first pair of antennse has the first joint short and deeply excavated for the 

 reception of the ophthalmopoda ; the two succeeding joints are short and hairy, and 

 the two fiagella do not reach beyond the extremity of the rostrum. The second 

 pair carries a long, narrow scaphocerite, and a flagellum that scarcely reaches beyond the 

 distal extremity of the rostrum. 



The second pair of gnathopoda is robust, and reaches to half the length of the 

 rostrum, the terminal joint being fringed with short, spine-like hairs. 



The first pair of pereiopoda is nearly as long as the gnathopoda, but more slender. 

 The second pair is minutely chelate, with a long multiarticulate carpos. The three 

 following pairs are subequal, the posterior being the shortest and the anterior the longest, 

 and have the lower or posterior margin of the meros sparsely dentate with small spine- 

 like points. The carpos is smooth, about one-third the length of the meros, and is 

 produced anteriorly to a small tooth on the propodal articulation ; the propodos is 

 smooth, and nearly, but not quite, as long again as the carpos ; the dactylos is long, 

 slightly curved, and sharply pointed. 



The outer plate of the rhipidura has a diaeresis armed with a small tooth on the outer 

 margin ; the inner plate is narrow and rounded terminally ; it is fringed with long hairs, 

 as is also the inner margin of the outer plate, and both are a little longer than the 

 telson. 



Observations. — The specimens of this species were taken at the same station as 

 Plesionika spinipes, to which they bear a general resemblance, although they differ in 

 the relative lengths of the pereiopoda, rostrum, and antennae, and have proportionately 

 larger eyes, and a differently formed rostrum. The meral joints of the three posterior 

 pairs of pereiopoda resemble one another in the two species in having numerous little teeth 

 along the posterior margin. 



The branchiae are arranged according to the typical condition in the genus ; attached 

 to the coxa of each pereiopod there is a small, almost rudimentary, mastigobranchial 

 appendage, so diminished in size as to be apparently only a useless appendage. 



Among the specimens appear to be two females, but of one I am uncertain. 



(ZOOL. CHALL. ESP. — PART LII. — 1887.) Fff 82 



