1046 THE VOYAGE OF H.M.S. CHALLENGER. 



on a quasi-apex, beyond which the true apex is decurrent, and has on its lower or inner 

 margin four short but strong spines; the fifth joint scarcely longer than the fourth, 

 narrower at the base than elsewhere, laminar, with the front and hind margins smooth, 

 slightly convex, the distal margin obliquely truncate, having four small sharp spines with 

 accessory threads at the front, and two or three at the back ; the finger lanceolate, as 

 long as the fifth joint, with a short setule at the back where the narrow sharp nail 

 commences. 



Pleopods. — The coupling sjoines sinuous, with a large lateral retroverted tooth on one 

 side, and on the other a row of six or seven small teeth succeeding the apical tooth ; there 

 are also many plumose setae on the peduncles ; the cleft spines numbered six in the ramus 

 examined, the longer arm being obviously serrate on the inner side ; the outer ramus 

 had twenty joints. 



Uropods. — The peduncles of the first pair a little shorter than the longer ramus, with 

 many spines along the upper margins, and a submarginal series near the lower border ; on 

 the inner distal margin there is a small tooth and a long spine ; the rami are slender, 

 somewhat curved, apically acute, the lower longer than the upper, but much less con- 

 spicuously spined ; the peduncles of the second pair quite as long as the rami, reaching 

 much beyond those of the preceding pair ; of the upper edges the inner has many spines, 

 the outer few but longer ones ; the rami are broad, reaching little beyond the preceding 

 pair, the upper rather longer than the lower, both with curved acute tips, the upper 

 edges fringed with many spines, the lower ramus having a second series ending near the 

 apex with a spine of great length, distally denticulate ; the peduncles of the third pair 

 much shorter than the rami, apically produced below, the upper margin carrying a small 

 group of spines ; the rami lanceolate, subequal, reaching much beyond the other pairs, the 

 upper one with its upper margin smooth, except for a small feathered spine near the top, 

 the lower margin serrate, armed with spines and feathered setae, the lower ramus rather 

 the longer, serrate on both margins, setiferous. 



Telson longer than the peduncles of the third uropods, nearly twice as long as its 

 greatest breadth, cleft for more than three-quarters of its length, not dehiscent, the sides 

 at first almost parallel, then converging gently to the distal end ; the apices slightly 

 emarginate, each having a spine and a cilium, the inner corner slightly more produced 

 than the outer ; several small spines are dotted about the surface of the telson. 



Length. — The specimen, in the position figured, measured, in a straight line from the 

 front of the head to the apex of the third uropods, three-fifths of an inch. 



Loccdity.— Station 167, off New Zealand, June 24, 1874; lat. 39° 32' S., long. 

 171° 48' E. ; depth, 150 fathoms ; bottom, blue mud. Four specimens. 



Remark. — The specific name is given in compliment to my obliging friend, Mr. Charles 

 Chilton, of New Zealand, who is doing so much good work upon the Sessile-eyed Crustacea. 



