THE LOACH 159 



False pearls are made by introducing this pearl mixture 

 into very thin bulbs of glass, some of which are blown in 

 irregular shapes, to increase the resemblance to real pearls. 

 Liquid white wax or gum arabic in solution is afterwards 

 injected into the beads to make them solid ; the glassy surface 

 is then slightly dulled by exposure to the vapour of hydro- 

 fluoric acid, and the illusion is so complete as to deceive all 

 but expert scrutiny. 



Fourteenth Sub- Family : COBITIDINAj THE LOACH GROUP 



This group is formed of a number of genera of small 

 fishes, none of them more than a few inches in length, 

 distributed over the Old World and not represented in the 

 New. Externally they suggest connection with almost 

 anything rather than the last group described the breams 

 resembling miniature barbels or gudgeon more than any other 

 of the carps. The body is greatly elongated, the mouth is 

 always surrounded by barbules, never less than six in number, 

 and the air-bladder is partly or wholly enclosed in a bony 

 capsule. Of the three European genera, two only are 

 represented in Britain, each by a single species. 



The Loach (Nemachilus barbatulus] 



FINS. 



Dorsal : 9 or 10 rays. 

 Anal : 6 or 7 rays. 

 Ventral : 7 rays. 

 Pectoral : 12 rays. 



TEETH. 

 Pharyngeal, in a single series. 



The genus Nemachilus thread-tipped consists of about 

 fifty species, distributed in a wide range from the Malay 

 Archipelago through Asia and Europe as far west as Ireland, 

 but not represented in Denmark or Scandinavia. Of all 

 these numerous species, only one, Nemachilus barbatulus^ is 



