SALMO RAPPIL 297 



rake-teeth on the last gill-arch is seven to eight. They often assume a paired 

 arrangement. 



The scales in the fore-part of the trunk are relatively large, so that, 

 although the number of scales in the lateral line does not differ materially 

 from that of the Salmon Trout, the number between the shoulder-girdle and 

 the hinder extremity of the pectoral fin is very different, amounting to fully 

 thirty in the Austrian Salmon Trout, while in this fish it is usually fifteen or 

 sixteen, rarely twenty to twenty-two. A part of this difference may be attri- 

 buted to the longer pectoral fin of the Austrian Salmon Trout, but it is partly 

 due to the larger scales of the Lake Garda Trout. As compared with the 

 Salmon Trout there is one ray more in the anal fin. 



The number and length of the pyloric appendages, according to Giinther, 

 varies from forty to fifty, and, therefore, more resembles S. lacustris than S. 

 marsiglii. We are hardly prepared, however, to attach great importance to this 

 character, there being some evidence to show that it varies with food. 



The Lake Garda Trout is characterised by the comparative paucity and small 

 size of the black spots which cover the body, though these spots are more 

 numerous and rather larger on the sides of the head. All the fins are unspotted. 



The species is not known to attain a greater length than fifteen inches. 

 It is commonly regarded as not migrating, but we learn through Canestrini 

 that while it occurs in the lakes of Lombardy and Venetia, it is reputed to 

 descend the rivers to their mouths, and enter the sea. 



It spawns during the month of December. It has long been known under 

 the name of Carpione, and highly valued as food. It is also termed by the 

 Italians Trnlta del Lago ; and is similarly known in the Southern Tyrol as 

 Lack&forelle. 



Salmo rappii (GUNTHER). The Bottom Trout of 

 Lake Constance. 



D. 13, A. 12, P. 13, V. 10. Scales : lat, line 120, transverse 2735. 



The Grund-forelle is so named from its habit of frequenting the bottom, to 

 distinguish it from the Schweb-forelle, which remains visibly suspended in the 

 water. There is very little difference in the fins, and Salmo rappii has a ray 

 more in the anal, and often an extra ray in the ventral. There may be one 

 vertebra less, and the number of pyloric appendages is considerably fewer, 

 varying, according to Giinther, from forty-eight to fifty-four. It is a fine fish, 

 growing to a length of three feet, and is limited to Lake Constance. The head 

 is rather depressed, and the body has a plump, thick, stouter build than in 

 Salmo lacustris. The snout is generally rather obtuse, and becomes elongated 



