242 ZOOLOGY 



The term "minnow" is applied to two distinct families of 

 small fish. One of these is also known as " killifish." The 

 killifish have a broad head covered with scales, and have 

 well-developed teeth in the month. They occur in schools 

 in shallow water on the shore, and ascend streams to their 

 sonrce. They are carnivorous, and feed at the surface. 

 In one species from the Southern coast, Heterandria l for- 

 mosa, 2 the male is only about two centimetres long, and is 

 the smallest known vertebrate. Our commonest species on 



FIG. 225. Fumhdus heteroclitus, a killifish or shore minnow. Xat. size. 



Photo, by W. H. C. P. 



the shore, or in brackish water, is Fiindiilm 3 heteroclitus 4 

 (Fig. 225). The minnows of the other family have a nar- 

 row head without scales, and with no teeth in the mouth. 

 They occur exclusively in fresh water, and are known as 

 "shiners." The " goldfish" is related to this group. 



The pike and pickerel (Esox 5 ) are roughly cylindrical 

 fishes, with large mouth, elongated, depressed jaws, and 

 strong, hooked teeth. 6 They are large, voracious, fresh- 

 water fishes, confined, with the exception of a single species, 

 to the United States. The " muskallunge " of the Great 



s, different ; <ii>r)p, avdpos, man, male. 2 Comely. 



3 fundus, bottom. 4 erepo/cXtros, irregular or unusual. 



5 f<ro, a fish living in the Rhine, mentioned by Pliny. 



6 Fig. 220. 



