SORTATION. 



39 



sharp edge, but, unlike all of them, its dorsal fin is placed above the 

 anal, much nearer the tail than the head. The character of the pike 

 is betrayed by the teeth, which are so characteristic that we must 

 find room for a sketch (Figs. 20 and 21). Look at the array on the 

 vomer, and note how the palatines on each side of it are armed, and 



Fig. 21. DENTARY OF PIKE. 



how those on the premaxillary are kept small, so as not to obstruct 

 the entrance into the capacious mouth ; look at the miscellaneous 

 assortment, large and small, on the dentary, that is, the tooth-bear- 

 ing portion of the lower jaw ; and, in addition to all these, there are 

 teeth on the tongue and hyoid bones. Compare this formidable 

 dental armament with the modest array of the carp (Fig. 22), which 

 has teeth only on the lower pharyngeal bones. 



Now for the other genera, two and two. In the first two the 

 abdomen is rounded throughout, but the dorsal is in the middle of 

 the back ; these are Carassius, with 5 to 7 rays in the anal, and 

 Leuciscus, with 8 to IT. Of Carassius there are two species, the gold- 

 fish (C. auratus), which is reddish-golden and silvery, frequently 

 marked more or less with black, and varying so much in its fin 

 structure, that it can only be distinguished from C. vulgaris (the 

 crucian carp) by the number of scales in its lateral line, the goldfish 

 having under 30, the other having more than 30, but the colour is 



guide enough, the crucian carp being 

 greenish above, with yellow sides 

 and pinkish abdomen, which the 

 goldfish never has. 



A genus of much more importance 

 to the angler is Leuciscus, with its 8 

 to ii anal rays. It includes the 

 roach, the chub, the dace, the rudd, 

 and the minnow. In four of these 

 the lateral line runs from head to 

 tail ; in the minnow it does not, in 

 fact, in technical phrase, it is " incom- 

 plete," although made up of from 80 

 to go scales. As a rule the minnow 

 Fig. 22. LOWER PHARYNGEAL is distinguishable by its small size, 

 TEETH OF CARP it being generally some three inches 



or thereabouts in length, but as a few 



giant specimens are on record, running up to seven inches, it is as 

 well to keep an eye on the incomplete lateral line. The four others 

 have the line complete, and though easily recognisable when side by 

 side are not so easy of description. The safest way is to count the 

 rows of scales between the lateral line and the ventrals. If there are 



