93 



blue, which adds to the general intelligent look of the fish. 

 The head region occasionally assumes a darker hue Its 

 generic name Gymnocroiaphus refers to the fact that the head 

 and cheeks are devoid of scales. 



It is well provided with a row of sharp, curved (hence specific 

 name), closely-set cutting teeth, and it does not hesitate to use 

 these effective weapons on any of its fellow fish who chance 

 to incur its displeasure. It is, however, of a very social dis- 

 position towards fish of its own kind, and becomes greatly 

 excited when another is introduced into the tank. On one 

 occasion a single specimen was kept for a considerable time in 

 a tank along with other fish, and showed every sign of pleasure 

 when another of its kind was introduced, circling around it 

 and assuming a peculiar attitude — the body held almost verti- 

 cally with the head downwards, the tail fin and posterior part 

 of the dorsal and anal fin keeping up a trembling motion. 

 (Compare the same action observed in the Harder.) It also 

 had previously shown exactly the same phenomenon when a 

 painting of the fish itself was held up in front of the tank. 



The only instance of a psychological state resembling 

 amusement or hilarity in a fish was observed in the case of the 

 John Brown. The interpretation of the observation may be 

 erroneous, but the fact of the occurrence was as follows : — On 

 one occasion a small Barbel, or Barger as it is sometimes 

 called [Galeichthys feliceps) was put into the tank. Unhke the 

 adults, small forms move about actively in the day time. Six 

 long feelers project from the chin of this fish, and these seem 

 to be its chief sensory organs in searching for food. This little 

 fish, which moves busily about the tank, sweeping the ground 

 with the long feelers, was on one occasion observed to be 

 passing backwards and forwards over the John Brown lightly 

 touching the surface of his sides and back with the points of 

 the long feelers. The John Brown occasionally lay over on his 

 side to facilitate this operation, and frequently became greatly 

 excited, opening the mouth widely and extending the gill- 

 covers on each side to their utmost, the whole body and fins 

 occasionally quivering with excitement under the apparently 

 tickling process. This sometimes became too much for him 

 and he would suddenly break away, still with shaking body 

 and widely-expanded mouth and gill-covers. After a pause 

 he would again seek out the Barbel, and the process was re- 

 peated till finally the Barbel left him, apparently after having 

 removed the Copepods which occurred on his body. 



These Copepods were not parasitic, but moved about freely 

 on the skin of the fish, and could not ha\'e caused any serious 

 [C.P. 6— '14.J 



