11. COEEGONUS. 177 



snout. The labials are a little longer than in C. qrmclrilateraUs ; and 

 their posterior pieces are of a different shape, being ovate, whereas 

 they are acutely elliptical in the other. The under jaw measures a 

 very little more than one-half the length of the upper surface of the 

 head ; and when the mouth is distended its tip is exactly even with 

 the end of the snout. Jaws and palate toothless ; four longitudinal 

 rows of teeth on the tongue. 



The middle between the tip of the snout and end of the scales is 

 at the thirty-second scale of the lateral Une, and opposite to the third 

 ventral ray, or tenth dorsal one. There are eight scales between the 

 dorsal and lateral line, and as many between the latter and the ven- 

 trals. Total length 14 inches, length of the head 2 inches. 



Musquaw River (Gulf of St. Lawrence). 



6. Coregonus nasus. 



Salmo (Coreg.) nasus, Pallas, Reise, iii. p. 705. 



Tschir, Lepechin, Reise, iii. p. 227, taf. 13. 



Salmo nasutus, Pallas, Zoogr. Ross.-As. iii. p. 401. 



[Coregonus nasutus, Cuv. 8f Val. xxi. p. 493, is evidently a very dif- 

 ferent species, as appears from the description of its snout, both 

 jaws being said to be of equal length.] 



D. 13-14. A. 15. 



SesquipedaHs, vix ulnaris. Forma cyprinacea. Caput corpora 

 crassius, vix compressum, rostro brevissimo, retuso, ante oculos con- 

 vexo, gibbo. Os exiguum, cyprinaceum, laeve ; maxilla superior 

 longior, quam clauso ore gibbus nasi paulo exsuperat. Nares in 

 ipso gibbo. Periophthakaium latum. Corpus macrolepidotum, lati- 

 usculum, crassum, compresso-convexum, dorso ante pinuam obtuse 

 angulato et per breve spatium adscendente Color argenteo-albus, 

 lateribus caerulescens, supra lineam lateralem fuscescens. Pinnae 

 omnes caerulescentes, inferae basi albidae ; appendix ventialiura tri- 

 quetra, bre\'issima, vix squamis emergens. Longitudo descripti 

 speciminis a summo tuberi rostri ad extrema pinnae caudae 1' 6" 0'", 

 3apitis ad operculorum oram 3", a summo rostro ad apicem lamina - 

 rum mystacearum 7'" (adeoque rictus brevissimus) ; ad oculum 7", 

 ad pin. pectoralem 3'", inde ad ventralem 4" 6'", inde ad analem 

 4" 9'", hujus latitudo 1" 11'", inde ad caudam 1" Q>\"', eujus longi- 

 tudo 2" 6"'. A summo item rostro ad pin. dorsi 7" 6'", hujus lati- 

 tudo 2", inde ad adiposam 3" 11|"', cujus latitudo lO^'", inde ad 

 pin. caudae 1" 6'". Corporis latitudo summa ante pin. dorsi 4" 3'", 

 crassities ibidem 2" 1'", capitis altitudo ad nueham 2" 4'", crassities 

 1" 7"'. Pondus hujus trilibri minus ; in foemina 1" T" , aequante fere 

 4 librarum. (Pallas.) 



Arctic Sea, periodically ascending the rivers Ob, Jenisei, and 

 Kolima. 



