MARINE CRUSTACEANS. 703 



considerably the shorter and half narrower.' This description given by Dana agrees excellently 

 with our specimens, except that in them the inner ramus of the uropods extends slightly 

 beyond the telsonic segment, and the outer ramus is as in Dana's own figure a little over half 

 as broad as the inner. The hind margin of the head is concave. The second and third segments 

 of the peraeon are rather shorter than the rest. The eyes are large, black, wide apart, so 

 that their size is more apparent in a ventral than a dorsal view. 



The upper antennae are separated only by the meeting apices of the head's underfolding 

 triangular rostral point and the pentagonal frontal lamina. The first two joints of the peduncle 

 are only faintly separated, and the third joint is subequal in length to the two combined ; 

 the first joint of the nine-jointed flagellura is much shorter than the second, the whole 

 reaching a little beyond the peduncle of the second antennae. In these the first three joints 

 are short, the fifth slightly longer than the fourth, the elongate flagellum in the specimen 

 examined consisting of 21 joints. 



The mouth-organs are characteristic of the genus. 



The limbs are of the same general type as in the preceding species, the sixth joint in the 

 first gnathopod is considerably broader than in the two following pairs of legs. Dana observes 

 that ' the fourth joint of the third pair is a little shorter than either the third or fifth pairs, 

 and longer than the tareus.' In our notation this should read that the fifth joint is a little 

 shorter than the fourth or sixth, and longer (but only a little longer) than the seventh. 



In the telsonic segment there are four spines on each side of the bifid apical point. 



Colour (in spirit) light, with brown speckling of very variable density. 



Length 5 mm. by a breadth of 2 mm. or a little over. Dana gives the length as three 

 lines, which would be something more than 6 mm. 



Locality. North Mal^ Atoll, 35 fathoms, hard sand ; Hulule ; Suvadiva Atoll, 44 fathoms, 

 hard muddy bottom; Kolumadulu Atoll, 38 fathoms, mud and weed. 



Dana obtained the species from Straits of Balabac, north of Borneo, Whitelegge fi-om 

 'sponges in sandy pools' at Funafuti Atoll, Borradaile also from Funafuti, 'three examples 

 found on weed in the lagoon, one dredged in the lagoon in 1.5—25 fathoms of water.' 



A specimen from Minikoi, noted as an 'Isopod living in tentacles of large tubicolous worm 

 (Polychaeta 4),' measured 5 mm. in length, by only 1-25 mm. in breadth. But after drawing 

 and dissecting it I could find no character but the narrowness to separate it from Dana's 

 species. It was a female, but not carrying eggs or young. The marsupial plates have the 

 hind margin cut into a firinge. 



Fam. Corallanidae. 



Corallanidae (part), 1890, Hansen, Vid. Selsk. Skr., Ser. 6, Vol. y. Pt. 3, p. 280 ; Alcironidae, 

 1890, Hansen, Vid. Selsk. Skr., Ser. 6, Vol. v. Pt. 3, pp. 285, 312, 390; 1893, Corallanidae (part), 

 Stebbing, History of Crustacea, p. 345 ; Alcironidae, 1893, Stebbing, History of Crustacea, p. 346 ; 

 Corallanidae (part), 1901, Richardson, Proc. U.S. Mus., Vol. XXIII. p. 517; Alcironidae, 1901, 

 Eichardson, Proc. U.S. Mus., Vol. xxiii. p. 519. 



In 1895 Dr H. J. Hansen reduced these two families to the rank of subfamilies. Whatever 

 the systematic dignity allowed them, they must, I think, be united. Were the Alcironidae inde- 

 pendent that group would naore properly take its name fi-om Tachaea of Schiodte and Meinert, 



