134 SALMONIDJi:. 



l>-d. Adult, mature specimens, 9 inches long. Lake of Llanberris. 



Presented by T. P. W. Ellis, Esc]. ; caught in March. 

 e-f. Immature specimens, 8 inches long, with the belly silvery. 



Lake of Llanberris. Presented by T. P. W. Ellis, Esq. ; caught 



in March. 

 (J. Six inches long. Lake of Llanberris. Presented by T. P. W. 



Ellis, Esq. ; caught in September. 

 h. Four and a half inches long. Lake of Llanberris. Presented by 



T. P. W. EUis, Esq. ; caught in February. 

 i-lc. Adult. From the Haslar Collection. 



Ucscrlj^tiun of a iMale specimen, 9 inches long. 



Body rather compressed and elongate ; its greatest depth, which 

 is below the origin of the dorsal fin, is contained five times or four 

 times and one-thii-d in the total leijgth (without caudal). The least 

 depth of the tail is three-fifths or two-thirds of the length of the 

 base of the dorsal fin. The height of the head above the mandi- 

 bulary joint e(|uals the distance between the posterior margin of the 

 orbit and the end of the operculum. The upper profile of the head 

 is not elevated above the margin of the orbit, and is slightly concave. 

 The diameter of the eye is one-fifth of the length of the head, two- 

 thirds of the extent of the snout, and more than one-half of the 

 width of the interorbital space ; the latter is flat, wdth the median 

 ridge and the lateral series of pores scarcely visible. Snout rather 

 depressed, conical, with the lower jaw slightly cui-ved upwards and 

 overreaching the U2)per. The nostrils are situated midway between 

 eyeball and end of snout ; the anterior is round, open, surrounded 

 by a membrane, which posteriorly is developed into a small flap 

 nearly entirely covering the smaller, oblong, posterior nostril. By 

 this character alone the Torgoch may be distiug-uished from the 

 Charr and Freshwater Herring. The maxillary extends to (or scarcely 

 beyond) the vertical from the posterior margin of the eye, and is 

 armed with 19-21 teelh of moderate size ; six or seven teeth in each 

 intermaxillary, seventeen in each mandible ; seven teeth on the vomer, 

 forming two sides of a triangle, the point of which is directed back- 

 wards ; fifteen teeth on each palatine ; five pairs on the tongue. The 

 suhoperculum is produced backwards, covering the triangidar portion 

 of the humerus above the root of the pectoral, and being in immediate 

 contact with the latter ; the vertical width of the suhoperculum is 

 one-half, or rather less than one-half, of that of the oijerciilum. Only 

 three hrmwMosteyals are exposed in a lateral view of the fish, the 

 others being situated at the lower side of the head. The lower 

 branch of the outer branchial arch is provided with thirteen lanceo- 

 late straight gill-rakers ; the longest is somewhat less than two lines 

 long in the specimen described. 



The origin of the dorsal fin is somewhat nearer to the snout than 

 to the root of the caudal ; the length of its base is not much less than 

 its height. The fifth and sixth rays form the rounded top of the fin. 

 The first ray is rudimentary, the second half as long as the third, the 



