SALMONID^E. 131 



Genus IV. — Thtmallus, Guvier. 



Brancliiostegals seven to ten : pseudobranchiai well developed. Body somewhat 

 elongated and compressed. Gape of mouth small : maxilla short, rarely extending 

 to beneath the middle of the orbit. Minute teeth on the jaws, near the head of the 

 vomer, and on the palatines : none on the tongue. First dorsal with many rays 

 (20-24 rays) : second dorsal Jin adipose : caudal forked. Stomach siphonal. Scales 

 rather large. Lateral-line ivell marked. Pyloric appendages rather numerous. 

 Air-bladder very large. 



Geographical distribution. — Temperate portions of the northern hemisphere, 

 generally restricted to fresh waters. 



1. Thymallus vulgaris, Plate CXXIV. 



QvpaXkoQ, iElian, Lib. xiv, c. 22. 



Thymallus seu Thymus, Belon. De Aquat. p. 184; Salvian. fol. 81, t. xvi; 

 Rondel, ii, p. 187 ; Gesner, pp. 978, 979 ; Aldrov. v, c. 14, p. 594 ; Jonston, iii, 

 tit. i, c. 3, p. 128, t. xxvi, f. 3, 4, and t. xxxi, f. 6; Willughby, p. 187, t. N.8; 

 Kay, p. 62. Coregonus, no. 3, Artedi, Synon. p. 20, Genera, p. 10, Species, p. 41. 

 Salmo, Gronov. Zooph. no. 375. Trutta, Klein, Pise. MSS. v, p. 21, no. 15, t. iv, 

 f. 5. Grayling, Pennant, Brit. Zool. (Ed. 1776) iii, p. 311, pi. lxi (Ed. 1812), iii, 

 p. 414, pi. lxxii ; Low, Fauna Oread, p. 224 ; Davy, Salmonia, 1832, p. 198. 

 Duhamel, Peches, ii, p. 218, pi. iii, f. 2. 



Salmo thymallus, Lin. Syst. Nat. i, p. 512; Bloch, Fishe Deuts. i, p. 158, 

 t. xxiv ; Gmel. Linn. p. 1379 ; Bonn. Ency. Ich. p. 167, pi. lxix ; Bl. Schn. p. 410 ; 

 Donovan, Brit. Fisb, v, p. lxxxviii ; Pall. Zoo. Ross. -As. iii, p. 364 ; Turton, Brit. 

 Fauna, p. 104 ; Gronov. ed. Gray, p. 153. 



Salmo thymus, Bonnaterre, 1. c. p. 167. 



Coregonus thymallus, Lacep. v, p. 254 ; Flem. Brit. An. p. 181 ; Jurine, Poiss. 

 Lac Leman, pi. vi. 



Thymallus vulgaris, Nilss. Prod. Ich. Scan. p. 13, and Skand. Fauna Fisk. 

 p. 447 ; Jenyns, Manual, p. 430 ; Bonap. Pesc. Eur. p. 23 ; Kroyer, Dan. Fisk. iii, 

 p. 35, c. fig. ; Yarrell, Brit. Fishes (ed. 1), ii, p. 79, c. fig. (ed. 2), ii, p. 136 

 (ed. 3), i, p. 304; White, Catal. p. 80 ; Thompson, Nat. Hist. Ireland, iv, p. 167 ; 

 Schlegel, de Dier. Ned. p. 133 ; Siebold, Sus. w. f. Mit. Eur. p. 267 ; Giinther, 

 Catal. vi, p. 200 ; J. Warnimont, Pub. de l'lnst. de Luxen. xi, pp. 1-48 ; Collett, 

 Norgcs Fiske, p. 171 ; Feddersen, p. 78 ; Canestrini, Fauna Italia, Pesc. p. 23 ; 

 Houghton, Brit. F. W. Fish. p. 149, c. fig. ; Moreau, Poiss. France, iii, p. 543 ; 

 Giglioli, Cat. Pesc. Ital. p. 42. 



Thymallus vexillifer, Agass. Mem. Soc. Sc. Nat. Neuch. i, t. B, t. D, f. 5-8, and 

 Poiss. d'eau douce, pis. xvi, xvii, xviio. ; Cuv. and Val. xxi, p. 438 ; Heckel and 

 Kner, Suss. w. f. p. 242 ; Blanchard, Poiss. deseaux douces, France, p. 437, f. 113. 



Thymalus gymnothorax, Cuv. and Val. xxi, p. 445, pi. 625 ; Giinther, Fische des 

 Ncckars, p. 117. 



Grayling, Couch, Fish. Brit. Isles, iv, p. 280, pi. cexxviii. 



B. vii-x, D. 20-24 (-*-:f 7 ) | 0, P. 15-16, V. 10-11, A. 11-14 (f.^y), C. 21, 

 L. 1. 75-85, L. tr. T -*:f 3, Ccec pyl. 22, Vert. 39/22. 



Length of head 5£ to 6, of caudal fin 6, height of body \\ to 5 in the total 

 length. Eyes — diameter of each 4 in the length of the head, 1| diameters from 

 the end of the snout, and about the same distance apart. Its form is rather 

 elongated and excessively graceful ; dorsal profile more curved than the abdominal. 

 Upper jaw very slightly the longer ; the posterior extremity of the maxilla reaches 

 to beneath the anterior edge or first third of the orbit. Teeth — fine ones in the 

 jaws, near the head of the vomer, and on the anterior portion of the palatines ; 

 none on the tongue. Fins — these vary with the sex, the last dorsal rays are 



9 * 



