ON MYSIS. 27 



tail, according to Fabricius, are rouiuled — inMons.De.smarets 

 figure, they appear obtusely pointed ; he also figures the 

 anterior scales as obtusely pointed, serrated, and ciliated 

 all round their margin (as in M. vulgaris), and the front 

 of the corselet obtuse. The My sis Fabricii inhabits the 

 sea about Greenland, and constitutes with the Mysis 

 pelagicus, the principal food of the whale, (Balsena 

 mysticetus.) 



Dr. Leach having observed that some of the species of 

 Mysis, had the middle scale of the tail notched, while in 

 others it remained entire, has divided the Genus into cor- 

 responding sections ; the former species or Mysis Fabricii, 

 together with the two following species, belong to the 

 section with a notched tail, the remainder are referable 

 to his second section. 



Mysis Leachii, (the M. spiniilosus of Dr. Leach.*) Tlie 

 specific names hitherto imposed, not being consecrated by 

 long usage, and being founded in a too partial knowledge 

 of the Genus, such of them as seemed likely to mislead, 

 have been changed for others less objectionable ; thus the 

 specific appellation given by Dr. Leach to the present 

 species, would be equally applicable to the most of those 

 with which we are acquainted, the same may be said of 

 the trivial wsawQ Jiexuosus employed by Muller. The INIysis 

 Leachii, although not sufficiently distinguished from the 

 following species, by the characters assigned in the note, 

 appears to differ obviously in colour and habitudes, and 

 although the former is rather a doubtful guide, yet in 

 the absence of more precise distinctions may be found an 

 useful auxiliary. Colour Avhen alive, pellucid cinereous. 

 Eyes black, red at their base. Laminse of the head with 

 a black longitudinal line and spots, every segment of the 

 body with a reddish rust coloured arborescent spot. Tail 



* Mysis, Cauda lamella intermedia externe spinulosa, apice acute emargi- 

 nata -. lamellis exterioribus acurainatis, latissime ciliatis. Linn. Traus. Vol. XI, 

 p. 350. 



