REPORT ON THE AMPHIPODA. 1599 



joint longer than the fifth ; the fifth than the fourth ; the finger straight, about a fifth of 

 the length of the preceding joint. 



Fourth Peraeopods. — The third joint as long as the fourth and fifth together, all 

 three pectinate along the front margin, the third having large teeth alternating with sets 

 of three or sometimes two or four minute ones, at the slightly produced apex having 

 only little ones. 



Fifth Peraeopods. — The rounded end of the side-plate is separated from the segment 

 by an open notch. The first joint is as broad and as long as in the preceding pair, as long 

 as all the remaining joints together ; the third is slender, straight, longer than the 

 fourth ; the fourth about equal to the fifth ; the finger straight, very minute. 



Pleopods. — The peduncles not very stout; in the cleft spine the subapical dilatation 

 is unsymmetrical, the arm that carries it reaching a little beyond the other ; the joints 

 of the rami six in number, the first joint long. 



Uropods. — Peduncles of the first and second pairs elongate, longer than the rami, 

 reaching back nearly on a level ; the rami having the margins pectinate with long 

 decurrent teeth; the rami of the first pair equal, in the second pair the outer ramus a 

 little shorter than the inner, the latter reaching a little beyond the rami of the first pair, 

 but not so far as either apex of the third pair ; peduncles of the third pair a little shorter 

 than the rami, about a third as long as the peduncles of the first pair ; the outer ramus 

 shorter than the inner, the edges of both pectinate like those of the other pairs. 



Telson three times as long as broad, with a very acute apex reaching beyond the 

 uropods. The telson and uropods are slightly spotted with orange. 



Length, about two-fifths of an inch. 



Locality. — Off Mindanao, Philippines, surface. 



Remarks. — The specific name is taken from the locality. From Oxycephalic longiceps, 

 Claus, it is well distinguished by the narrow neck, the more prolonged double-segment 

 of the pleon, the much longer peduncles of the second uropods, besides the minuter 

 details connected with the gnathopods and peraeopods. 



Genus Calamorhynchus, Streets, 1878. 



1878. Calamorhynchus, Streets, Proc. Acad. Nat. Sci. Philad., p. 285. 



1887. „ Bovallius, Systematical List of Amph. Hyper., Bihang till K. Svensk. 



Vetensk.-Akad. Handl., Bd. 11, No. 16, p. 39. 



For the original definition of the genus, see Note on Streets, 1878 (p. 485). The 

 character there given, " superior antenna? with the peduncle three-jointed ; in the female 

 straight," does not entirely suit the Challenger species, in which these antennae are 

 curved or sinuous ; that which the definition regards as the third joint of the peduncle 



