82 



SALMONID^. 



5. "The form of the caudal fin in specimens of a given size, age, and sexual development." 



6. "A great development of the pectoral fins when constant in individuals from the same 

 locality." 



7. "The size of the scales, as indicated by the number of transverse rows above the 

 lateral line." Dr. Giinther regards this as one of the most constant characters. 



8. "The number of vertebrae; the constancy of this character is truly surprising, excess 

 or diminution in the number being of rare occurrence." 



9. "The number of pyloric appendages." In some species the number varies from 

 thirty to fifty; in others, as in the Salmon and Charr, it is very constant; in the Lochleven 

 Trout these caecal appendages are generally very numerous, from seventy to ninety; and 

 where the normal number is diminished, this has been brought about by the confluence of 

 some of the caeca. I may mention a striking instance of the value of this character in the 

 case of the Galway Sea Trout {Sahiio gallivensis) ; in a specimen before me, a fish about ten 

 inches long, the pyloric appendages are very short, the longest is not more than half an 

 inch, and about a line in diameter. 



Certain points in the life history of the Salmon or other species of the Salmo7iida which 

 yet remain obscure will be noticed in the accounts of the different fish as they come before 

 me. I give here a tabular arrangement of the various species of British Salmonida, which I 

 hope will be found useful. 



SALMONID.E. 



FIRST GROUP— SALMONINA. 



First Sub-generic Group— SALMONES. 



MIGRATORY SPECIES. 



Salmo salar, Lin., (Salmon.) 



S. trutta, Flem., (Salmon- or Sea-Trout.) 



S. cambricus, DoNOV., (Sewen.) 



S. brachypoma, Gthr., (Short-headed Salmon.) 



S. gallivensis, Gthr., (Galway Sea-Trout.) 



S. argenteus, Guv. "c Valenc, (Silver Salmon.) 



S. erio.x, Yar., (Bull Trout of the Coquet.) 



NON-JJIGRATORY SPECIES. 



Salmo fario, LiN., (Common Brown Trout.) 

 S. ferox, Jard. & Selby, (Great Lake or Black 



Lough Trout.) 

 S. stomachicus, Gthr., (Gillaroo Trout.) 

 S. nigripinnis, Gthr., (The Black-Fin.) 

 S. levenensis, Walk., (Lochleven Trout.) 



Second Sub-generic Group — SAL VELINI. 



non-migratory species. 



Salmo alpinus, Lin., (Alpine Charr.) 



S. willughbyi, Gthr., (Windermere Charr.) 



S. perisii, Gthr., (Llanberris Charr.) 



S. grayii, Gthr., (Gray's Charr.) 



S. colei, Gthr., (Lord Enniskillen's Charr.) 



S. killinensis, Gthr., (Loch Killin Charr.) 



Coregonus clupeoides, Lac, (Gwyniad of Bala.) 

 C. pollan, Thomps., (Pollan, or Fresh-water 



Herring of Ireland.) 

 C. vandesius, Rich., (Vendace of Loch JMaben, 



Dumfriesshire.) 



Thymallus vulgaris, Xilss., (Grayling.) 



migratory or non-migratory. 

 Osmerus eperlanus, Lin., (Smelt or Sparling.) 



SECOND GROUP— SALANGINA. 

 No British species; (rivers and seas of China and Japan.) 



