. Rapports de découverte. La découverte (navire) ; les expéditions scientifiques ; océan ; l'Antarctique, îles Falkland. 270 RAPPORTS DE DÉCOUVERTE Genre Tetrastemma Tetrastemma esbenseni, Ehrenberg, n.sp. (Planche XVI, figs. 4, 23 ; fig. 46, 47). Cette espèce n'est pas banal. Elle a eu lieu comme suit : 7. iii. 26. King Edward Cove, Géorgie du Sud, 1 (N 18). 9. iii. 26. Maiviken, sous les pierres, 7 (N 18). St 39. 25. iii. 26. L'OTL, 179-235 m. 2 (44) ; N 4-T, 20 (N 23, N 93, N 112). Saint-jean 123. 15. xii. 26. L'OTL, 230-250 m. 1 (N 18). Les longueurs et largeurs correspondantes ont été : 30-0, 07 mm., 90-0, o-8mm. ; 22-0, 07 mm., 53-0, 1-

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. Discovery reports. Discovery (Ship); Scientific expeditions; Ocean; Antarctica; Falkland Islands. 270 DISCOVERY REPORTS Genus Tetrastemma, Ehrenberg Tetrastemma esbenseni, n.sp. (Plate XVI, figs. 4, 23; Figs. 46, 47). This species is not a common one. It occurred as follows: 7. iii. 26. King Edward Cove, South Georgia, 1 (N 18). 9. iii. 26. Maiviken, under stones, 7 (N 18). St. 39. 25. iii. 26. OTL, 179-235 m. 2 (N 44); N 4-T, 20 (N 23, N 93, N 112). St. 123. 15. xii. 26. OTL, 230-250 m. 1 (N 18). The lengths and corresponding breadths were: 30-0, 07 mm.; 90-0, o-8mm.; 22-0, 07 mm.; 53-0, 1-3 mm. The body is thin, soft and round in section, tapering at the head and tail. The head is pointed and there is no neck between it and the body. There is a chevron groove be- hind the head, complete ventrally. The eyespots are arranged in four groups at the corners of a rectangle, the number in each group varying from one to six, the anterior groups usually containing more than the posterior. The colour is light yellow or yellowish red. The gut can usually be seen through the body wall. In the specimens which were separated as N 44 the vascular system was more engorged than usual and no eyes were seen (Plate XVI, fig. 23), but they were identified with the other forms from the sections. Form and colour of spirit specimens. The body is contracted and cylindrical (lengths 18 and 15 mm. with breadths of 1-4 and i-omm.). All colour is bleached and no eyes are visible. On clearing in cedar oil one specimen possessed the usual two pairs of eyes imperfectly formed, another had four large eyes and several small perfect brown cup-shaped eyes close to them. Two more variations are shown in Fig. 46. The proboscis is always small and thin. The armature consists of a main stylet 0-065 mm- long on a base 0-083 mm- and a curiously irregular accessory armature. One specimen had two ac- cessory reservoirs, one with five stylets and the other, which appeared to be double, with five and six st

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