REPORT ON THE AMPHIPODA. 1457 



inner ramus having the upper part of the margins smooth, the lower part strongly 

 denticulate. 



Telson triangular, as broad as long, a little longer and broader than the peduncles of 

 t he third uropods. 



Length, in the slightly bent position figured, one-fifth of an inch. 



Locality.— April 3, 1875 ; North Pacific ; lat. 24° 49' N., long, 138° 34' E.; surface; 

 surface temperature, 71°'5. Two specimens, male. 



Remarks. — The specific name is given in honour of Milne-Edwards, who instituted 

 the genus Phorcus. Two specimens, mounted in Canada balsam during the voyage, one 

 of which has been referred to above, are labelled " Amphipod, surface, Australia." They 

 are both males and evidently belong to this species. A specimen taken March 15, 1874 ; 

 south of Australia; lat. 39° 45' S., long. 140° 40' E. ; surface temperature, 60°-2, has 

 the inner ramus of the third uropods reaching as far back as the inner ramus of the 

 third pair, and the telson decidedly longer than broad. 



Dana's Phorcus hyalocephalus, from the Atlantic, is distinguished from both the 

 Challenger species by having the first two segments of the perseon nearly concealed. 

 "Phorcus Reynaudii" or " Baynaudii," as described by Milne-Edwards, has the second 

 segment of the thorax or perseon " notablement plus developpe qu'aucun des six autres 

 segmens," and, as described by Spence Bate, it has the fourth joint of the third pereeopods 

 longer than the third joint, the fifth of the same length and thickness as the fourth, and 

 the finger longer than the fifth joint and of the same diameter. In "Phorcus Loveni" 

 Bovallius, from the Caribbean Sea, the first gnathopods are said to be as long as the second, 

 and the first segment of the pleon is said to be shorter than the last two segments of the 

 perseon. 



The following table shows the distribution of the genus Phorcorrhaphis as illustrated 

 by the Challenger specimens : — 



1. Station 81, July 13, 1873; Atlantic, north-west of Madeira; lat. 34° 11' N., 

 long. 19° 52' W. One specimen (Phorcorrhaphis zamboangie). 



2. Off Australia ; surface. Two specimens (Phorcorrhaphis edwardsi). 



3. March 16, 1874 ; south of Australia ; lat. 39° 22' S., long. 142° 27' E. ; surface. 

 One specimen. 



4. March 15, 1874; south of Australia; lat. 39° 45' S., long. 140° 40' E. ; surface. 

 One specimen. 



5. Station 288, October 21, 1875; South Pacific; lat. 40° 3' S., long. 132° 58' W. ; 

 surface. One specimen, nearly a quarter of an inch long (probably Phorcorrhaphis 

 zamboangse). 



6. Station 181, August 25, 1874 ; Pacific, between Api and Cape York ; lat. 13° 50' S., 

 long. 151° 49' E.; surface. Three specimens. 



(ZOOL. CHALL. EXP.— PART LXVII. — 1888.) X.XX 183 



