500 PISCES SUB-CLASS IILTELEOSTOML 



wards deposited in the inner side of thin glass balls, of which the small 

 aperture was finally closed with wax. An account of this manufacture will 

 be found in a small work on British fishes by Frank Buckland. On account 

 of the almost vertical position of the cleft of its up-turned mouth, mention 

 must be made of the sichel of Eastern Europe, which forms a genus (Pelecus) 

 sufficiently distinguished by this one characteristic. 



The rare and local British fish known as the spiny loach (Cobitis tcenia) is 

 the typical member of the second sub-family (Cobitiiwe) of the carp tribe ; a 

 group which includes several other genera of loaches, all confined to the 

 fresh waters of Europe and Asia. In all the members of this sub-family the 

 air-bladder is enclosed, either completely or partly, in a bony capsule, and 

 none possess false gills. The body, too, never has the deep form character- 

 istic of the carps, and in some groups is much elongated. Barbels, varying 

 in number from six to twelve, are always present, and the mouth is inferior 

 in position, with fleshy lips. Whereas the pelvic pair may be Van ting, the 

 median fins are devoid of spines, the number of rays in the dorsal being 

 variable, but those of the anal always few. The tail-fin is rounded, and the 

 scales, if present, are small, and buried in the mucus of the skin. One genus 

 from the Oriental countries is peculiar in possessing scales on the top and 

 sides of the head. The spiny loaches, of which there are at least three 

 species, take their name from the presence of a pair of forked spines below 

 the eyes ; such spines being capable of erection at the will of their owners. 

 In the large genus Nemachilus, which includes the common loach (N. barba- 

 tulus) of every English stream, the spines below the eyes are wanting, and 

 the upper jaw alone is furnished with barbels, of which there are three pairs. 

 The third European genus, Misyurnus, includes the giant loach of Europe, 

 and three other species ; its distributional area including Europe and Asia 

 north of the Himalaya. In this genus there are either five or six pairs of 

 barbels, two of which arise from the lower jaw. Many other genera are 

 found in the Oriental countries, and it is noteworthy that whereas the 

 European forms are inhabitants of clear running waters, these latter dwell 

 in tanks, where they bury themselves in the mud at the bottom. All, how- 

 ever, agree in that their food is composed exclusively of animal substances. 



In the fresh waters of Tropical Africa the place of the loaches is taken by 

 the two species of the genus Kneria, which form a family by themselves, 



distinguished from the Cyprinidce by the absence of throat, 

 Family or pharyngeal teeth, the simple, undivided form of the air- 

 Kneriidce. bladder, and the absence of barbels. 



Of far more importance than the last is the very exten- 

 sive family of fresh-water fishes commonly known as characinoid fishes, but 

 which might perhaps be termed the southern carps. Their distribution is 



indeed largely complementary to that of the Cyprinidce, since 



Family they are confined to Central and South America, and Africa 



Erythrinidce. south of the Sahara ; carps being absent from the former 



countries, although present in the latter. This peculiar 

 geographical distribution is one among many instances of the close affinity 

 existing between the faunas of these two areas. The explanation of 

 the absence of the Cyprinidce from South America may possibly be that 

 the characinoids entered Africa at the time when that country was in 

 communication with South America, whereas the carps did not come in till 

 that communication was severed. If that be so, the Cyprinidce must have 

 come into Africa at the same time as many of the large mammals, such as 



