260 Rev. Canon A. M. Norman on British Myslda. 



Mysis relicta^ Lovdn. 



1861. Mysis relicta, Loven, Oi^fversigt af Vet.-Akad. Forhand. p. 285. 



1867. Mysis oculnta, var. relicta, G. O. Sars, Hist. Nat. des Crust, 

 d'eau douce de Norwege, i. p. 14, pis. i.-iii. 



1868. Mysis relicta, Kessler, Materialia ad cognoa. lacus Onegae, p. 78, 

 pi. i. figs. 1 a-d. 



1870. Mysis relicta, Jarzynsky, Prsemissus Catal. Crust, decap. invent, 

 in mari albo kc. p. 317. 



1872. Mysis diluvianus, Stimpson, MS., Hoy, Trans. Wisconsin Acad, 

 vol. i. p. 100 (no description). 



1871. Mysis relicta, S. I. Smith, Amer. Journ. Sci. and Arts, vol. ii. 

 p. 5. 



1874. Mysis relicta, S. I. Smith, Report 1872-3 Commission Fish and 



Fisheries, p. 643, pi. i. fig. 2. 

 1879. Mysis relicta, G. 0. Sars, Carcinol. Bidrag til Norges Fauna, 



I. Monogr. Mysider, p. 73, pi. xxxii. 

 1882. Mysis relicta, Czerniavsky, /. c. fasc. ii. p. 8, fasc. iii. p. 51, pi. xv. 



figs. 17-20, pi. xvi., and pi. xvii. fig. 1. 



Form rather slender ; anterior portion of cephalothorax 

 subequal in breadth to earlier segments of pleon ; hyaline, 

 with arborescent pigment-cells. Eyes large, pyriform ; 

 peduncle long ; almost the whole of the cornea projected 

 beyond the sides of the cephalothorax. Antennules having 

 the peduncle long and moderately stout, basal joint as long 

 as the two following. Antennal scale in form as a long 

 ellipse, fully one fourth longer than peduncle of antennules 

 and four times as long as broad ; greatest breadth subcentral ; 

 ciliated all round, and right down the outer margin to the very 

 base ; apical joint bearing four setaj. Legs having the tarsus 

 much longer than the preceding joint and composed of six to 

 seven articulations, of which the first is much the longest ; 

 nail very slender and setiform. Telson gradually tapering, 

 with straight sides ; length to greatest breadth as 5 to 2 ; 

 cleft shallow and very broad and open, about one seventh the 

 length of the telson ; sides of telson with about sixteen spines, 

 which are crowded towards the base, but widely separated 

 towards the extremity, and the most distal anterior to the 

 cleft. Inner iiropods with only four or five spines on the 

 anterior two thirds of the inner margin. Fourth pleoijods of 

 male having the basal joint of moderate length and the inner 

 branch as usual, but the outer branch remarkably short, not 

 twice the length of the inner. Length IS raillim. 



Hah. Lough Neagh, Ireland {A. M. N.). 



Distrihution. Lakes Vettern, Venern, Malar, and other 

 lakes in {Sweden {Loven c& Lilljehorg) ; Lake Mjosen, Norway 

 [G. 0. Sars) ; Lake Onega, Russia, and Lakes Ladoga and 

 Putko, in Finland (Jarzynsky) ; northern part of the Gulf of 

 Bothnia, but not observed south of Quarken ; Kallavesi, 



