132 THE VOYAGE OF H.M.S. CHALLENGER. 



fectly separated from the anterior with five, and the posterior with twenty-five, more or 



less small teeth. The anterior frontal margin is furnished with one large and two small 



rostral teeth. Dorsal ridge without teeth or spines, but bead-like tubercles traverse the 



median line and the posterior margin of the carapace. Pleon carinated, the four anterior 



somites each projecting to an anteriorly-directed tooth. Ophthalmopoda lodged in a deep 



notch in the dorsal surface of the anterior margin of the carapace. Meros of the first 



pair of pereiopoda smooth except a small tooth on the outer distal angle, and two near 



the external distal angle of the carpos, and one small one on the inner. Fifth pair of 



pereiopoda terminating in the male in a long, slender, sharp, styliform dactylos, and in 



the female in a short and stunted chela (fig. 1 o, ?). 



The dorsal armature of the carapace may be thus formulated — 



Marginal, . . . ... . . 12—5—25 



Rostral, . . . . . . . 3 



Dorsal crest, . . . . . . . 



Length — male, 80 mm. (3'3 in.); female, 85 mm. (3 - 6 in.). 



Habitat— Station 173, July 24, 1S74 ; lat. 19° 9' 35" S., long. 179° 41' 50" E.; 

 off Matuku ; depth, 310 to 315 fathoms ; bottom, coral mud. 



The carapace is of a long quadrate form, the lateral margins being nearly parallel, 

 slightly converging at each extremity, and adorned with a great number of small teeth. 

 The anterior division has ten or twelve, but between them is a considerable quantity of 

 small hairs that fill the intervening spaces, particularly in the younger animals. The 

 central division has four or five similar teeth, and hairs, but their separation from the 

 anterior is not always very perfectly defined. The posterior division is more distinctly 

 separated, and carries about twenty-five or twenty-six teeth, not very clearly defined, which 

 gradually diminish in size. The lateral wall of the carapace below the serrate margin 

 is perpendicular for some distance, and then flattened inwards at almost right angles. The 

 perpendicular portion is covered with long hairs, especially visible on the lower margin, 

 where there is a row just above a line of very fine teeth that form a ridge between the 

 vertical and the horizontal portion of the lateral w T all of the carapace ; the horizontal part is 

 slightly granular, and between the granules the surface is perfectly smooth. 



The anterior margin of the carapace (fig. 1 c) has the lateral angles projecting slightly 

 in advance of the central or rostral point, which consists of a strong tooth arisiug from 

 the metope, directed obliquely upwards and forwards, and flanked by two small teeth, one 

 on each side behind on the frontal margin of the carapace, and a row of hairs, on the outer 

 side of which a serrate margin passes outwards and forwards to a point, from which it 

 recedes also as a serrate margin to the inner angle of the orbit, where a short and slender 

 tooth projects. The outer angle of the orbit is also armed with a sharp and slender 

 tooth, whence obliquely to the outer angle of the carapace are several small, sharp teeth. 



