583 



orbicular, witli dark red pigment. Sujierior anteniup in female not nearly 

 attaining halt' the length of the bod\% l^tt joint of the peduncle much the 

 largest, 3rd scarcely half as long as the 2nd, flagellum not exceeding the 

 peduncle in length, and composed of ahoi^t 15 articulations, very sharply 

 marked of from each other, and having on Loth edges a small recurved bristle. 

 Inferior antennae somewhat longer than the superior, and rather strongly 

 built, with the flagellum exceeding half the length of the peduncle and 

 unusually thick, being composed of about 10 articulations. Both ])airs of 

 antennae in male considerablj' more elongated than in female, though otherwise 

 of a similar structure. Anterior gnathopoda exactly alike in the two sexes, 

 carpus rather short, triangular, propodos about twice its length and oblong 

 oval in form, with the palm rather short. Posterior gnathoj)oda in female 

 considerably stronger than the anterior, with the propodos rather large and 

 broad, oval quadrangular in form, palm nearly transverse and defined below 

 by a distinct angle, dactjdiis strong and, like that of the anterior ones, 

 minutely denticulate inside; those in male still more powerfully developed, 

 having the propodos extremely large and expanded, with tlie jmlm somewhat 

 flexuons, and defined below by a distinctly projecting angle. Anterior ])airs 

 of pereiojioda with the basal joint oval subfusiform in outline; the 3 posterior 

 pairs successively increasing in length, basal joint oval in form, that of the 

 antepenultimate pair somewhat shorter, Init scarcely broader than that of the 

 last 2 pairs, propodal joint considerably expanded at the end, exlybiting a 

 distinct palm armed with 3 .strong spines, the outmost of which is much curved 

 and unguiform. Last pair of uropoda with the rami sube(iual in size, the 

 outer one armed with 2 very strong recurved hooks, the inner one with 

 several slender bristles at the obtusely truncated tip. Telson, as seen from 

 above, subtriangular in shape, outer jiart rapidly tapering, and terminating 

 in 2 juxtaposed, very strong, hooked projections. Colour, according to Mr. 

 Stebbing, a liright yellowish green, with sparse but conspicuous black dots. 

 Length of adult female (i mm, of male 7 mm. 



Retnarks. — There cannot, in my opinion, be any doubt, that the 

 two forms described by Sp. Bate as Pleonexes (Ampliithoe) gammaroides and 

 SunaniphithoU hamulus are only the male and the female of one and the same 

 species, for which the iiame first proposed by that author ought to be retained. 

 Boeck also described the 2 sexes as 2 different species, identifying the female 

 with Sp. Bate's species Sunamphithoe hamulus, whereas the male is descril)ed 

 as a new s]iecies of the same genus, under the same of S- longicornis. I have 

 had an opjiortunity of examining the somewhat defect type specimen of the 

 latter, preserved in our Museum, and cannot find any other differences from 

 male specimens of the present species than that the antennae are unusually 



