38 
seems to be the fact of his being unable to determine the small 
specimens. G. marinus he considers ,a shallow water form of the 
typical G. locusta". 
In his paper Crustacea Neerlandica (Tijdschrift der Nederland. 
Dierkund. Vereenig., ser. 2, Deel 2, Afl. 3, Leiden 1889) Hoek 
has given a very elaborate description and some figures of the 
species in question; but with exception of G. marinus, the other 
species (G. loc., G. pulex and G. Dueb.; G. Zaddachi was not in- 
stituted at that time) are considered varieties of G. locusta, but 
— as"far I may understand his Dutch text — without giving real 
reasons for his theory. 
The affinities between the species in my material from Ran- 
ders Fjord seem to be as follow 
G. locustg G. locusta var. Zaddachi 
(salt and brackish water) fresh, brackish and salt water 
G. Duebenii - — G. pulex 
'brackish water) fresh water 
but I must say that at present it is impossible to prove more than 
the fact that G. Zaddachi is derived from G. locusta. 
Gammarus locusta L. 
Gammarus locusta Sars, Account vol. 1, 1895, p. 499, Pl. 176, fig. 1. 
— — Stebbing, Amphip., Tierreich 1906, p. 476 (lit. 
and syn.). 
EN — … &Hoek, Tijdschr. Nederl. Dierk. Vereen., Ser. 2. 
Deel 2, Afl. 3, 1889, p. 206, Pl. 10, fig. 10, 10', 
PE 7, fg. 10 
tr — … Sexton, Schriften d. Physik.-åkonom. Gesellschaft 
zu Kånigsberg i. Pr., Jahrg. 54, 1913, p. 90, Pl: 
4, fig. 3. 
— — … Sexton, Zool. Soc. Proceedings 1912, p- 656, Pl. 
F3; He: 3 
This species is distinguished by the form of the lateral cornerS 
of the cephalon, the distinct nodular projections of the urosomé, 
the broad and great reniform eyes; (2. joint of p5 produced 2! 
