Irish Fishes of the Genus Coregonus. 485 



Subsp. a. Coregonus gracilior. 

 The Derwentwater Vendace. 



Coregonus gracilior, Regan, Ann. & Mag. Nat. Hist. (7) xvii. 1906, 

 p. 181, pi. vii. 



Depth of body 4 to 5 in the length, length of head 4^ to 5. 

 Snout nearly as long as or shorter than eye, the diameter of 

 which is Z\ to 4 in the length of head and nearly equal to 

 the interorbital width. Lower jaw projecting; maxillary 

 extending to below the anterior \ of eye, its length about \ 

 the length of head. 25 to 29 gill-rakers on the lower part of 

 the anterior arch. 60 to 72 scales in a longitudinal series, 7 

 or 8 in a transverse series from origin of dorsal tin to lateral 

 line, 6 or 7 between lateral line and base of pelvic fin, 17 to 

 21 round the caudal peduncle. Dorsal with 8 to 10 branched 

 rays ; origin equidistant from end of snout and base of caudal 

 or a little nearer the former ; longest ray § to £ the length of 

 head. Anal with 9 toll branched rays. Pectoral extending 

 from \ to nearly § of the distance from its base to the pelvics, 

 which are inserted below or a little behind the origin of the 

 dorsal. Caudal peduncle \\ to 2 as long as deep, its least 

 depth \ to | the length of head. {Silvery, back bluish ; tins 

 pale. 



Derwentwater and Bassenthwaite Lakes, Cumberland. 



Thirteen specimens, measuring up to 190 mm. in total 

 length ; two of these have been presented by Mr. S. Venour, 

 four are in the Keswick Museum, and the remainder have 

 been received from Mr. H. A. Beadle. Two have 10 branched 

 rays in the dorsal tin, eight 9, and three 8. 



2. Coregonus pollan. 

 The Pollan. 



Coregonus pollan, Thompson, Proc. Zool. Soc. 1835, p. 77; Giinth. Cat. 

 Fish. vi. p. 194 (1806) ; Day, Fish. Britain, ii. p. 129, pi. exxiii. 

 fig. 2 (1884). 



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

 5. Snout as long i.s or a little shorter than eye, the diameter 

 ol which is 4 to 4| in the length of head ; interorbital width 

 3^ to 3£ in the length of head. Jaws equal anteriorly ; 

 maxillary extending to below anterior -J- of eye or beyond, its 

 length f to ^ the length of head. 22 to 26 gill-rakers on 

 the lower part of anterior arch. 74 to 86 scales in a longi- 

 tudinal series, 8 to 10 in a transverse series from origin of 

 dorsal fin to lateral line, 1\ to 9 between lateral line and base 



Ann. & Mag. X. Hist. Ser. 8. Vol. ii. 35 



