216 "TERRA NOVA" EXPEDITION. 



similar to the first two, all ending in strong curved claws." That is to say, using 

 the terminology now in vogue for the appendages of Crustacea, that in P. typicum 

 the second, third, seventh and eighth thoracic limbs are similar in general form, and 

 form a sharp contrast with the fourth, fifth and sixth, while in P. p>unctatissimum the 

 second, third and eighth are similar, and in contrast with the fourth, fifth, sixth and 

 seventh. The specimens of both species which I have examined bear out these 

 descriptions, and the form of the seventh pair of thoracic limbs forms a valid and 

 sharp specific character. 



P. typicum, Chilton, has so far only been recorded from Lyttelton Harbour, and 

 that only once, when discovered by Chilton in 1883. 



Sub-family SPHAEROMINAE. 

 A. SPHAEROMINAE HEMIBRANCHIATAE. 



Genus BXOSPHAEROMA, Stebbing, 1900. 



24. Exosphaeroma gigas (Leach). 



K gigas, Stebbing, 1900, p. 553, pi. XXXIX ; Hansen, 1905 (1), p. 118. 



Occurrence. — Stations 133, 135 and 136, Spirits Bay, near North Cape, New 

 Zealand, four, quite juvenile. 



ReiTiarhs. — These specimens are quite small and immature, and are, with doubt, 

 referred to this common New Zealand species. 



25. Exosphaeroma falcatum, sp. nov. PI. V, figs. 1-8. 



Occurrence.' — Station 133, Spirits Bay, near North Cape, New Zealand, plankton, 

 two males and one female (types). 



Description. — A hemi-branchiate Sphaeromid, with the body smooth, without 

 granules or tubercles, but presenting a minutely honeycombed appearance dorsally 

 under the microscope. Head with a distinct though small rostral projection, with a 

 distinct excavation at each side of its base, into which the antennules fit and are just 

 visible from dorsal view. Below the rostral process and in front of it projects the 

 large epistome, very prominent in dorsal view. The epistome is figured in pi. V, 

 fig. 8, and in side view is distinctly dorsally recurved, giving a very pug-nosed 

 appearance to the animal. Coxal plates almost hidden in dorsal view, and strongly 

 curved on to the ventral surface. Telson broadly triangular in shape and strongly 

 convex, without tubercles or granules, apex bluntly and rather broadly rounded. 

 Uropods in the male (pi. V, fig. l) almost reaching the apex of the telson, inner ramus 

 narrowly ovate and bluntly pointed, outer ramus very narrow, curved slightly out- 

 wards and sharply pointed ; uropods in the female (pi. V, fig. 2) exactly as in the 



