THE TRUE FISHES. 



171 



Carps (Cyprinida). The carps comprise many spe- 

 cies, and abound in nearly all streams throughout the 

 Old World and North America. They have weak, tooth- 

 less jaws. The 

 stone-toters (Ex- 

 oglossuni) build 

 nests by carrying 

 stones, which they 

 pile in heaps. The 

 dace (Fig. 212), 

 common minnows, 

 and shiners, are 

 all related. FIG. 212. Black-nosed dace. 



NOTE. The dace (Rhinichthys atrdnasus) is one of the most inter- 

 esting of the nest-building fishes. During the breeding-season males 

 and females clear away a spot, perhaps under the water-lilies, and in 

 the oval depression the eggs are deposited, the pair covering them with 

 a layer of stones ; then another layer of eggs is deposited, and another 

 of stones, until a mound of eight or ten inches in height is the result, 

 and here the young are hatched. 



Blind, Cave-Fishes (Amblyopida). These comprise 

 three genera and four species of ghostly, sightless fishes 

 (Fig. 213) living in the limestone caves of the Middle and 



FlG. 213. Blind-fish (Amblyopsis}, Mammoth Cave. 



Southern States. Though blind, they are supplied with 

 sense-organs so delicate that they are enabled to capture 

 fishes with eyes that have strayed into their domain. 



