REPORT ON THE AMPHIPODA. 709 



description of those in his Amaryllis macrophthalmus, in being " vertically elongated, 

 sub-crescentic" ; the upper antennas have seventeen joints to the primary flagellum, and 

 thirteen to the secondary. In Mr. Haswell's own description he assigns to the principal 

 flagellum " about thirty segments," and seven to the secondary ; in the form which he 

 calls Amaryllis hrevicornis he says that the principal flagellum has eighteen joints, and 

 the secondary five. This part would appear, therefore, to be very variable in the species. 



Genus Acontiostoma, n. gen. 



Body compact, head scarcely or not at all visible laterally. 



Upper Lip with a pointed apex. 



Mandibles long and narrow, without molar tubercle ; a small three-jointed palp set 

 close to the base. 



First Maxillie with the inner plate small, carrying one seta at the apex, the outer 

 plate with the apical spines set close together, the palp small, not reaching the end of 

 the outer plate. 



Second Maxillie with narrow plates. 



Maxillipeds with the shaft strong and bulky, the inner plates with a pointed apex ; 

 the outer plates more or less apically angular, without marginal spine-teeth, the palp with 

 its third joint longest, its fourth very small or rudimentary. 



First Gnathopods with the hands narrowing apically, not subchelate. 



Second Gnathopods with the hand and finger forming a feeble chela. 



Uropods short, those of the third pair with no more than a single tuberculiform ramus. 



Telson short, whole or emarginate. 



The generic name is derived from olkovtiov, a dart, crTofjia, a mouth, in allusion to the 

 shape of the upper li]D, and to point to the connection between this genus and Acidostoma 

 of Lilljeborg. Type species, Acontiostoma marionis. 



By Boeck, as well as by Lilljeborg (see Note on Lilljeborg, 1865, p. 362), Acido- 

 stoma is said to be without palp on the first maxillae; it has in fact a tubercle to 

 represent this palp, which in Acontiostoma, though small, is more decidedly in evidence ; 

 in the new genus the spines of the outer plate are not abnormal in structure and position 

 as in Acidostoma ; the palp of the mandibles is short instead of long ; in the palp of the 

 maxillipeds the first joint is shorter instead of longer than the second ; the third uropods 

 are almost or quite without rami, and the telson, instead of being deeply cleft, is whole, 

 or only a little emarginate. 



Acontiostoma marionis, n. sp. (PI. XXX.). 



Animal compact, with a remarkably solid integument, opaque, speckled with roundish 

 semi-transparent spots ; the head totally concealed in a lateral view, in which the animal 



