REPORT ON THE AMPHIPODA. 1393 



Second Perseopods like the first, but the first and fifth joints a little shorter. In all 

 the limbs gland-cells can be seen in the first joint, but in the first and second perseopods 

 they are much more conspicuous in the fourth than in the first joint. 



Third Perseopods. — First joint more or less oval, the lower end the wider ; the second 

 joint a little longer than broad ; the third shorter than the fourth, with a couple of 

 minute setules on the front margin ; the fourth joint shorter than the fifth, with the 

 front margin pectinate ; the fifth joint slender, very slightly curved, the front margin 

 pectiuate, and having a little apical inward curving spine ; the finger slender, curved, 

 about half the length of the fifth joint, with two little spinules on the front margin just 

 below the dilated base. 



Fourth Perseopods resembling the third, but with all the joints longer, and seemingly 

 without the two little spinules on the finger. 



Fifth Perseopods like the two preceding pairs, not longer than the third, the first 

 joint narrower, the terminal joints scarcely pectinate. 



Pleopods. — Coupling spines small, with two pairs of retroverted teeth ; the cleft 

 spine with the arms nearly equal, the longer one having, as is probably the case 

 in the kindred species, a small ddatation near the apex, this dilatation being so placed 

 as to antagonise with the other arm just below the dilated part of that arm ; joints 

 of each ramus six in number. 



Uropods. — Peduncles of the first pair longer than the rami ; the rami narrowly 

 lanceolate, with the adjacent margins pectinate, the longer inner ramus more strongly 

 than the outer ; peduncles of the second pair a little longer than the outer ramus, shorter 

 than the inner, the rami nearly as long as those of the first pair, which they nearly 

 resemble ; peduncles of the third pair nearly as long as those of the first, longer than 

 the rami, which are subecpial, the adjacent margins finely pectinate ; in all the rami 

 there is a scarcely perceptible pectination also of the outer margin. 



Telson triangular, longer than broad, a little more than half the length of the peduncles 

 of the third uropods. 



Length, in the position figured, from front of head to extremity of uropods, just over 

 one-tenth of an inch. Some of the specimens were much smaller. 



Locality. — April 26, 1876; off St. Vincent, Cape Verde Islands; lat. 16° 49' N., 

 long. 25° 14' W.; surface temperature, 73° - 2. 



Remarks.— The specific name — meaning divided chin, and derived from the Greek, 

 (Txilfi), I cleave, and yeWiof, a chin — refers to the emarginate lower border of the head, 

 which is a very conspicuous feature in this species. There are many points of resemblance 

 between this species and Hyperia dysschistus found at the other side of the world, but 

 the general shape and proportions are distinct, and the descriptions wdl have shown that 

 in many minute detads the two species differ. There is, however, a single specimen, 



(ZOOL. CHALL. EXP. — PART LXVII. — 1888.) Xxx 175 



