458 TUBE-BLADDERED GROUP. 



quently into Britain it is said early in the seventeenth centuiy. The ordinary 

 form is shown in the upper figure of the illustration on p. 457 ; but there are many 

 domesticated varieties, differing either in the form of the body or the size and 

 arrangement of the scales. Among the latter, one of the most remarkable is the 

 so-called spiegel-karpfen (mirror-carp), shown in the right-hand middle figure of 

 the illustration. In this variety, which is found only in ponds, the scales are three 

 or four times the normal size, and instead of covering the whole body are arranged 

 in from one to three longitudinal rows, with bare skin between them. In Western 

 Europe the carp has taken kindly to its new habitat, not unfrequently attaining as 

 much as a yard in length, with a weight of 25 Ibs., while very much larger specimens 

 are on record. Preferring still waters, with a soft muddy bottom in which it 

 grovels with its snout for food, the carp feeds on various vegetable substances, as- 

 well as on insects and other small aquatic invertebrates. When the surface of their 

 haunts is locked in ice, carp lie deeply buried in holes in the mud, frequently 

 consorting in numbers, and undergoing a partial hibernation, which is not broken 

 till the returning warmth of spring. Their growth is extremely rapid, and their 

 fecundity extraordinary, nearly three-quarters of a million eggs having been counted 

 in the roe of a medium-sized specimen. They are capable of living a considerable- 

 time out of water, especially if they are moistened from time to time ; and are 

 known to live to a very great age. Carp will interbreed both with the Crucian 

 and golden carp. 



Crucian and Easily distinguished by the absence of barbels, the Crucian carp 



Golden Carp. (Carassius vulgaris\ and the golden carp, or gold-fish (C. auratus}- 

 are the best known representatives of another closely allied genus; the former 

 being a native of Central and Northern Europe, but also found in Italy and Siberia,, 

 while the home of the second is China and the warmer parts of Japan. Both are 

 comparatively small species, and have been long domesticated ; whereas, however^ 

 the Crucian carp always retain the original brownish colour, the domesticated 

 variety of the golden carp has assumed the well-known golden tinge from which 

 it takes its name ; an albino form being also known. Among the numerous varieties- 

 of this fish the most curious is the so-called telescope-fish, shown in the right-hand 

 figure of the illustration on p. 412, taking its name from the prominence of the 

 highly movable eyes, and likewise characterised by the great development of the 

 caudal fin. In Europe gold-fish thrive best in waters heated somewhat above the 

 ordinary temperature, and they are accordingly frequently kept in engine-ponds, 

 where the water may have a temperature of some 80, and in which they breed 

 freely. The Crucian carp, shown on the left of the illustration on p. 457, is con- 

 fined to ponds and lakes, where it seeks the deepest parts. 



Barbels Represented by some two hundred species from the tropical and 



temperate regions of the Old World, the barbels are best known by 

 the common European species (Barbus vulgaris), shown in the lower figure of the 

 illustration on p. 457, and the gigantic mahasir (B. tor) of India and Ceylon. 

 Agreeing with the carps in the structure of the anal fin, and the position of the 

 lateral line and dorsal fin, they belong to a subgroup of genera in which there ar& 

 generally not more than nine rays in the dorsal fin, the pharyngeal teeth being 

 arranged in three rows, the greater part of the cheek not covered with bone, the 



