REPORT ON THE AMPHIPODA. 617 



flagellum ; in the lower antennae the fifth joint of the peduncle may be a little longer or 

 a little shorter than the fourth ; the spines of the first maxillae vary much in general 

 appearance, in this as in other species, according as they are fresh or worn with long use. 

 To the ramus of the second uropods I should have attached more importance had I not 

 found in a small light-coloured specimen the ramus shaped just as in the large dark- 

 coloured specimens. 



This species, in respect of the antennae, mouth-organs, second gnathopods, peraeopods, 

 and general structure of the pleon, closely resembles Anonyx gulosus, Kr0yer, the Anonyx 

 cicada (0. Fabricius) of this Report (see pp. 46, 47). It differs from it in respect of the 

 first gnathopods and the second uropods, in these two respects agreeing with Ichnopus, 

 Costa, as defined by Bocck, but from that genus it difi'ers in regard to the maxillipeds and 

 the branchial vesicles, which are pointed below, but without the pectinate folds considered 

 characteristic in Ichnojous. Since, by the omission of the epithet ' ' quadrangulari, " as applied 

 to the hand of the first gnathopod, in Boeck's definition of Ano7iyx, that definition will 

 include the present species, it seems advisable by that expedient to save the creation of a 

 new genus. To' point to its agreement with the older species, I have therefore named the 

 new one Anonyx cicadoides. Anonyx pumilus, Lilljcborg, is retained by Boeck himself 

 in the genus Anonyx, although the hand of the first gnathopods is not quadi-angular. 



Genus Tryphosa, Boeck, 1870. 



For the original definition, see Note on Boeck, 1870 (p. 399). The genus is so near 

 to Anonyx, KrOyer, as defined by Boeck himself, that they ought perhaps to be reunited, 

 as suggested both by G. 0. Sars and Gerstaecker. 



Try2?hosa antennipotens, n. sp. (PI. VI.). 



Rostrum obsolete, lateral angles of the head acutely produced ; back well-rounded, 

 most dilated at the fifth segment of the peraeon ; postero-lateral angles of the third 

 pleon-segment not acute or upturned; fourth pleon-segment with a dorsal depression, 

 distally carinate, tip-tilted, the lateral margin continuous with the curve of the lower 

 margin of the third segment ; the sixth segment ridged on each side of the telson. 



Eyes indistinct, but apparently large, set back from the front margin, reniform, 

 meeting at the top of the head. 



Upper Antennas. — First joint long and tumid, second and third joints short, 

 narrowing distally, the distal borders sinuous ; first joint of the flagellum short, equal to 

 the four following, calceoli large and crowded, there being one on each of the fifty-two 

 joints of the flagellum, with the exception of the first and two or three at the end. The 



(zooL. CHALL. EXP. — PART Lxvii. — 1887.) Xxx 78 



