468 FISHES. 



spacious cavity behind tlie base of the pectoral fin, the inside 

 of which is coated with a reticulated mucous membrane. It 

 opens by a foramen m the upper part of the axil. Tliis 

 apparatus is the same which is found in many SiLuroid fishes, 

 and which has been noticed above, p. 192. There cannot be 

 any doubt that it is a secretory organ, but whether the 

 secretion has any poisonous properties, as in the Siluroids, or 

 as in Thalassophryne, has not been determined. No instance 

 of poisonous wounds having been inflicted by these fishes is 

 on record. Twelve species are known, the distribution of 

 which coincides with that of the family ; one very fine species, 

 B. didactyhts, occurs in the Mediterranean. 



Thalassophryne. — The spinous dorsal is formed by two 

 spines only, each of which is hollow, like the opercular spine, and 

 conveys the contents of a poison-bag situated at its base. Canine 

 teeth none. 



Two species are known from the Atlantic and Pacific 

 coasts of Central America. The poison-apparatus is more 

 perfectly developed than any other known at present in the 

 class of fishes ; it has been described above, p. 192. The 



Fig. 208. — Thalassophryne reticulata. 



species figured, Th. reticulata, is not uncommon at Panama, 

 and attains to a length of fifteen inches. 



PoRiCHTHYS. — Two Small dorsal spines; a canine tooth on 

 each side of the vomer. 



Two species, from the Atlantic and Pacific sides of Central 

 and South America. 



