113 



Still another possible significance of the blowing-up process 

 may be indicated by an occurrence, the facts of which I obtained 

 from the observer. The " Leguaan," a large crocodile-like 

 lizard, is abundant in the rivers of the east coast, and on one 

 occasion one of these was found recently dead, having been 

 apparently choked in endeavouring to sw^allow a Blaasop, 

 which was found in an inflated condition, completely stopping 

 up the throat. Various species of Blaasop are specially abun- 

 dant in the lagoons and tidal rivers, in which the Leguaan 

 also occurs. 



A pecuhar action was observed in nearly all specimens of 

 this fish when first introduced into the tank. One tank is 

 lined w4th white tiles and the fish persisted in pressing their 

 prominent chin against this surface, paddling meanwhile 

 energetically with their fins as if to force their way through 

 the tiles. This action was kept up for days until the skin of 

 their chin was rubbed through producing a large open wound. 

 They occasionally rubbed in the same way against the glass 

 front of the tank. No explanation of this was apparent. 

 Their behaviour otherwise was quite normal and they took 

 food readily. 



Zee-slang {Heptatretus hexatrema, Miill.). 



This fish occurs abundantly in Table Bay and False Bay, 

 and many specimens have been kept alive. Usually they do 

 not thrive very well in the tanks. One specimen, however, 



" Sea Snakes " {Hcptatniiis hexatrema, Miill.) 



which found a hole in the rockwork of the tank, lived and 

 throve well for over two years, till it grew too big for the hole. 

 During this time an opportunity was afforded of obser\ing its 

 habits to some extent. It, however, only came out at night, 

 and usually lay with only the tip of its snout or tail projecting 

 from the hole during the day. It is well known among fisher- 

 men that other fish avoid the Zee-slang, and even the mucus 

 which is freely given off'from the surface of its body, so that a 

 [C.P. 6-'i4.] 



