112 Mr. C. T. Regan on the 



of Loch Rr.nnocli in Pertlisliire ; S. willugJihii, tlie Winder- 

 mere Char ; and S.perisii, the Torgoch of the mountain-lakes 

 of Carnarvonshire, \r\ spite of much that has been written 

 to the contrary, these four species are quite distinct, as will 

 be seen from a comparison of the descriptions given below 

 and from the diagnostic characters shown in the following 

 synopsis : — 



I. Snout obtuse ; lower jaw rounded anterior! v, shorter than the upper. 

 Interorbital width 3 to 3§ in the length of head, con- 

 siderably more than the diameter of eye ; least 



depth of caudal peduncle | to | the length of head ; 



182 to 21.0 scales in a longitudinal series 1. killinensU. 



Interorbital width 3§ to 4 in the length of head, scarcely 

 more than the diameter of eye ; least depth of 

 caudal peduncle 5 to | the length of head ; 158 to 

 180 scales in a longitudinal series 2. struanengis. 



II. Snout conical or subconical in the adult ; lower jaw pointed ante- 



riorl}'. 

 Jaws equal anteriorly (J $) or the lower the shorter 



( 5 ) ; interorbital region convex 3. willughhii. 



Jaws equal anteriorly (J $) or the lower projecting 



(<S ) ; interorbital region flat 4. perisii. 



1. Salvelinus killinensis. 



Sahno killinensis, Giinth. Proc. Zool. Soc. IS60, p. 609, pi. xl., and Cat. 

 Fish. vi. p. 130 (186G) ; Day, Fish. Britain, p. 113, pi. cxviii. tig. 1 

 (1884). 



Depth of body about 4 in the length, length of head 3f to 

 ^4 ( c? ) 0'" ^3 to 4f ( ? ). Snout obtuse, with upper profile 

 decurved, as long as or longer than eye, the diameter of wliich 

 is 4^ to 6 in the length of head. Interorbital region more or 

 less convex, its width 3 to 3^ in the length of head. Dentition 

 moderate; lower jaw shorter than the upper; maxillary extend- 

 ing nearly to below the posterior margin of eye or a little be- 

 yond, its length 2^ to 2.1 ( J ) or 2? to 2| ( ^ ) in the length of 

 head; lower jaw rounded anteriorly, its length 1^ to 1| (cj) 

 or 1? to If ( $ ) in the length of head. 9 to 12 branchio- 

 stegals. 14 to 16 short gill-rakers on the lower part of 

 anterior arch. 182 to 215 scales in a longitudinal series. 

 Dorsal with 9 to II branched rays, its ori^-in nearer to the 

 tip of snout than the base of caudal, the longest ray 5 to f 

 the length of head. Anal with 8 or 9 branched rays. Pec- 

 toral from I to as long as the head, extending f to | ( J ) or 

 ^ to f (?) of the distance from its base to the baseot pelvics. 

 Least depth of caudal peduncle 11 to 1^ in its length and § 

 to ^ the length of head. Back and sides plumbeous, belly 



