11. COREGONUS. 177 



snout. The labials are a little longer than in C. quadrilateralis ; 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 siu-face 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 line, and opposite to the third 

 ventral ray, or tenth dorsal one. There arc 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 Eiver (Gulf of St. Lawrence). 



6. Coregonus nasus. 



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



Tsehir, TiepecMn, Heise, iii. p. 227, taf. 13. 

 L Salmo nasutu?, Pallas, Zoogr. Ross.-As. iii. p. 401. 



[Coregonus nasutus, Cue. 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. 



Sesquipedalis, vix ulnaris. Forma cy|)rinacea. Caput corpore 

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

 vexo, gibbo. Os exiguum, cj-prinaceum, laeve ; maxiUa superior 

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

 ipso gibbo. Periophthalmium latum. Corpus macrolepidotum, lati- 

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

 angulato et per breve .spatium adscendente. Color argenteo-albus, 

 lateribus ca3rulescens, supra lineam lateralem fuscescens. Pinnae 

 omnes csenilescentes, inferse basi albidse ; appendix ventraliura tri- 

 quetra, brewsima, vix squamis emergens. Longitudo descripti 

 speciminis a summo tubcri rostri ad extrema pinna3 caudse 1' 6" 0'", 

 capitis 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 latitude 1" 11'", inde ad caudam 1" 6g"', cujus longi- 

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

 tude 2", inde ad adiposam 3" Hg'", cujus latitude 10^'", inde ad 

 pin. caudse 1" 6'". Corporis latitude summa ante pin. dorsi 4" 3'", 

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

 1" 7'". Pondus hujus trilibri minus ; in foemina 1" 7'", asquante fere 

 4 Ubrarum. (^Pallas.) 



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

 Kolima. 



