PvEPOKT ON THE AMPHIPODA. 131 



1 827- Johnston, George, born 1797, died 1855 (Hao;en). 

 1828. V o / 



Contrihitions to the British Fauna. By George Jolmston, M.D., Felloto of 

 the Royal College of Surgeons of Edinhurgh. The Zoological Journal, vol. iii. 

 From January, 1827, to April, 182S. Loudon, 1828, pp. 173-181, 490-491. 



Under " (Class. Crustacea. Order. Heterobranchia. Sect. Ampliipoda. Gen. Gammarus) Lamarck," 

 he described " 1. Gam. maculatus," from sea coast rear Berwick, with the observation, " it 

 belongs to Leach's restricted genus Gammarus, of which he has described four species. 

 Three of these are well known to me. His G. aquaticus is common here, as every- 

 where else in our wells and ditches; the G. locusta swarms in the pools left on the 

 recess of the tide ; and the G. marinus, remarkable by its strongly ridged back, is 

 frequently taken here, in great abundance, in the baskets used for catching crabs. Our 

 animal is quite distinct from any of these, nor can it be tlie G. Camylops, which I 

 have not seen, for that is characterized by having ' flexucus eyes,' a character not in the 

 least applicable to our G. maculatus." 



" 2. Gam. punctatus." "Hah. Amongst confervse in pools left by the tide, very common near 

 Berwick. Ohs. In the arrangement of Dr. Leach this is an Ampithoe. He describes one 

 species, the Cancer Gammarus ruhricatus of Montagu (Linn. Trans, ix. 99, tab. v. fig. 1), 

 which differs from ours in the following particulars : — it is of a "reddish, or pale pink" 

 colour ; the eyes are crimson, in ours brown, and so dark that if not attentively examined 

 they might be pronounced black ; the hands have no notch or fissure between their 

 articulations ; and, if Montagu's figure be correct, the outline of the body is difi'erent. 

 Moreover, in the description, Montagu makes no mention of the punctures on the dorsal 

 portion of the segments, a character not likely to have escaped the notice of that excellent 

 naturalist." 



" 3. Gam. dubius," which Johnston at one time thought synonymous with Pherusa fucicola, 

 Leach, but in Gammarus dubius " the basilar joint of the superior [antennae is] longer than 

 the second or third," and this species has " arms with nearly equal hands, monodactylc, 

 oblong, not much dilated, and sparingly ciliated," whereas he observes, " in the figure of 

 the Pherusa fucirula given in the Supplement to the Encyclopsedia Britannica, the second 

 joint of the superior antennaj is represented as elongated, the first pair of feet or arms 

 filiform without any hand, and the hand of the second jaair oval wath a very small claw. 

 There is also a considerable difference about the tail, the PJierusa having no terminal 

 conical jsrocesses. Other distinctions might be mentioned, but those already specified seem 

 of as high a value as many of those which divide the genera of Dr. Leach." 



" 4. Gam. nolens." "Hab. amongst confervse, not rare. Obs. To the preceding species I gave 

 the specific appellation dubius, since it seemed doubtful to which of the genera of Dr. Leach 

 it ought to be referred ; this I have named 7iolens, as it will arrange with none of them. 

 It seems allied to the Gammarus monoculoides (Linn. Trans, xi. 5, tab. ii. fig. 3.) of 

 Mr. Montagu." 



He enumerates as also occurring at Berwick, "the Talitrus Locusta and Orehestia littorea of Leach," 

 the Mm-a grossimana and Jassa pulchella of the same author, " the Gam. monoculoides of 

 Montagu," and " the CoropMum longicorne," all of them in abundance. 



At p. 490, the habitat of Gammarus punctatus is described. 



The description of Gammarus maculatus is quoted by Bate and Westwood, vol. i. p. 339, who 

 distinguish it from the later Gammarus maculatus of Lilljeborg, but can give no furtlicr 

 clue to its identification. There can, I think, be little doubt that it is the same as 

 Gammarus {Gammarojjsis) cruthrophthalmus, Lilljeborg, which must in that case receive the 

 name Gammaropsis maculatus, Johnston. Gammarus 2Junctatus is identified by Spence 



