172 SALMOXID^. 



the length of the head. The lower jaw is the longer. Coloration 

 nuiform, with a silvery band along the side. 



New Zealand. 

 a-f. Types of the species. From the Haslar Collection. 

 (j-h. Three and a half inches long. Waikato River. From Mr. G. 



Ki-cfFt's Collection. 

 i. Several specimens. Presented by Vice- Admiral Sir E. Belcher. 



11. COREGONUS*. 



Coregonus, sp., Artedi, Genera, p. 9. 



Coregonus, Cuv. Regne Anim. 



Coregonus et Argyrosomus, Agass. Lake Siqjer. p. .3.39. 



Body covered with scales of moderate size. Cleft of the mouth 

 small ; maxillary broad, short or of moderate length, not extending 

 behind the orbit. Teeth, if present, extremely minute and decidu- 

 ous. Dorsal fin of moderate length ; caudal deeply forked. Pseu- 

 dobranchiae well developed ; air-bladder very large. Stomach horse- 

 shoe-shaped ; pyloric appendages extremely numerous. Ova small. 



Inhabitants of the froshwaters of the northern parts of temperate 

 Europe, Asia, and North America ; many species periodically as- 

 cending from the sea, especially from the Arctic Ocean. 



The species of this genus are not less numerous than those of 

 Salmo, some having a very extended geographical range whilst 

 others are confined to very limited localities. They are less sub- 

 ject to variation than the Trout, and therefore more easily cha- 

 racterized and distinguished. Hence we find that naturalists who 

 look with distrust on the different species of Salmo, are quite ready 

 to admit those of Coregonus. The characters which are the most 

 reliable are the shape of the snout, the development of the maxillary, 

 the form of the supplementary bone of the maxillary, the length of 

 the mandible, the height of the body and tail, the position of the 

 dorsal, and the number of scales and vertebrae. The species, which I 

 know from autopsy, may be readily distinguished by these characters ; 

 and lengthened descriptions would be quite unnecessary, as they 

 would repeat only the characters of the genus or refer to individuals 

 only. However, not all previous authors have paid regard to these 

 characters ; and although but little doubt can be entertained that, in 

 many cases, they have described distinct species, this is inferred 

 rather from the localities where the fi.shes have been obtained than 

 from the account given of them. 



* The following species are so imperfectly described, that it must suffice to 

 notice them with a few words only : — 



l; Coregonus paltasii, Cuv. & Val. xxi. p. 483, from Russia, said to be closely 

 allied to Coreg. marwna from Northern Germany, and possibly comprised by 

 Pallas imder the name of Cor. hivaretus. L. lat. 100. 



2. A species from the Lake Pereslavle Zaleski, near Moskau, described and 

 figured by N. Ozeretskovsky, Mem. Acad. St. Petersb. ii. 1810, p. 376, tab. 21. 

 It belongs to the group with prominent, lower jaw. 



.3. Coregonus. angusficeps, Cuv. & Yal. xxi. p. 5.34, known from a figure only, 

 and said to have been obtained at the Saskatchewan River. 



