Jordan-Thompson : Notes on a Collection of Fishes. 



83 



tip of the snout and the mouth. Maxillaries short, over half as broad as 

 long, and e.xtending to center of adipose eyelid. Supplcmentaries ovate 

 and two-thirds the breadth of maxillaries; mandible articulating with 

 quadrate below posterior edge of pupil, slightly longer than the snout 

 and contained 3^3 in the head. Seventh or eighth developed ray of the 

 dorsal midway between the snout and base of the caudal. The longest 

 ray is nearly length of head, and when supine extends beyond tip of last 

 ray; edge of fin concave; base two-thirds length of the ray. Adipose fin 

 small, above the center of ana! fin. Caudal is as long as head, deeply 

 emarginate. Base of anal three-fifths length of head, 'its longest ray 

 slightly longer than its base, its shortest one-sixth the head, and its edge 

 concave; ventrals slightly longer than pectorals, which are two- thirds 

 the length of the longest dorsal ray. Lateral line, slightly curved ventrally 

 from both ends, is nearer the dorsal. Scales rather large, about half the 

 diameter of the eye, and as broad as long. Color is light, olive-silvery, 

 darker above, the dorsal and caudal fins edged with black, the others clear. 



Family THYMALLID^. 

 3. Thymallus arcticus (Pallas). Siberian Grayling. (Plate XXIII.) 



Salmo arcticus P.vllas, Reise, III, 1776, 35, 70 (Sob, Kobyma, Obi Rivers). 

 Thymallus arcticus Smith, Salmoniden, 1886, 199, tab. VIII, no. 27-28 (Yenisei 



River). — Berg, Ann. Mus. ZooL Petersb., XII, 1907, 507 (west Siberia, 



Kobdo River, northwestern Mongolia). 

 Salmo digitalis Block & Schneider, Syst. Ichth., 1901, 421 (after Pallas). 

 Thymallus pallasi Cuvier & V.^lenciennes, Hist. Nat. Poiss., XXI, 1848, 449 



(after Pallas). — Gunther, Cat., VI, 1866, 201 (after Pallas). — Berg, Ann. 



Mus. Petersburg, XII, 1907, 509 (Kolyma, Jana River). — Dybowski, Verb. 



Ges. Wien, XIX, 1869, 509 (Kolyma, Jana River). 

 Thymallus grubei Dybowski, Verb. Ges. Wien, XIX, 1869, 955, tab. XVIII, 



fig. 9 (Ohon, Ingoda, Amur Rivers). — Berg, Assn. Mus. Zool. St. Petersburg, 



XII, 1907, 509 (Amur Basin). 

 Thymallus grubeii var. baicalensis Dybowski, Verb. Ges. Wien, XXIV, 1874, 391 



(Lake Baikal). 

 Thymallus baicalensis Grati.\now, (Russian publication), Moskow, No. 3, 1902, 58. 

 Thymallus arcticus baicalensis Berg, Wiss. Erg. Baikalsee, Exp. Lief., Ill, Cata- 



phracti, St. Petersburg, 1907, 67 (Lake Baikal). — Berg, Ann. Mus. Zool. Patent 



1907. 507 (Lake Baikal, Amgun River). 

 Thymallus baicalensis Dybowski, Verb. Ges. Wien. XIX, 1869, 509 (Lake Baikal, 



Amgun River). 

 Thymallus microstoma Herzenstein, (Russian publication), 1883, 244 (Koscha- 



gatsch, Tschuja River, Altai, upper course of the Obi; name only). 

 Thymallus nikolskyi Kaschchenko, (Russian publication at Tomsk), 1899, 131 



(Altai, Tscharysch River, Katun River, Tom River, at Kusnatz). 



