41 
(No. 5) Arctic sea 720 57"N:0? 57 ES sur Deichmann 
1891. Several 3 abt. 30 mm. As No. 4 (but the eye typical); 
inner ramus of up3 a little too short. 
Ho: 6) W "of Scotland 669 N; 1104 W.C Thor? Sk 52; 
1903), 280 m. 1 9 with embryones, 26 mm. As No. 1, but inner 
ramus up3 not very short. 
(No. 7) Massachusetts, Packard ded., 1866, some Øg, abt. 
26—28 mm. As No. 1; inner ramus of up3 a little too short. 
Probably no hairs on the hind edge of the epimeral plate of third 
metasome segment, hind corner of which is too little acute. 
(No. 8) Labrador, Packard ded. 1866 /G. mutatus Lilljb.), 3 
spec. 16—21 mm. As No. 7; the eyes are now totally lost. 
(No. 9) Valentia Harbour (,Thor" St. 58, 1906), 2 spec. 14—19 
mm. In the smaller spec. up3 is lost. They seem to be some- 
what typical (the large one has just been in moulting); but they 
differ in being much more setose than shown by Sars, and having 
very highly developped dorsal projections on the urosome segments. 
— Further see the next species; localities see p. 49. 
Gammarus locusta L. var. Zaddachi Sexton (nom. nov.). 
Gammarus Zaddachi Sexton I. c. 1912, p. 657, PI. 73 (excl. fig. 3), 
174 88 0 12 
= om > Ho ror p 00, PLS 2 
at locusta var. A. Hoek |. c. 1889, p. 210, Pl. 10, fig. 11 
[HE 
In 1912 Mrs. E. W. Sexton has instituted this as a new spe- 
Cies; as I shall show below it is only a brackish water variety of 
G. locusta (vide: Intermediate form p. 43). 
Or the principal points of difference between this and the other 
Species of Gammarus, vide Mr. Sexton I. c. 1912, p. 661 and 
164013. 
As 6. locusta var. Zaddachi I have determined the specimens 
Combining the following characters: about 4 clusters of hairs on 
the underside of 1. joint of ant. 1; the chela of på in g broader 
than in Sexton's fig. of the same of G. locusta (Sexton 1913, 
Pl. 73 fig. 3); inner ramus of up3 distinctly shorter than 1. joint 
