DE. GtJNTHER ON THE FISHES OV CENTRAL AMERICA. 



43T 



lines. 



Total length 54 



Length of the head 16 



Width of the head 14 



Depth of the head 10 



Diameter of the eye 1 



Length of the caudal lin 8 



of the ventral fin 7 



93. THALASSOPHRTJfE RETicuL.\TA. (Plate LXVIII. fig. 2.) 

 Giinth. Proc. Zool. Soc. 1864, pp. 150, 155. 



D. 2|24. A. 24. V. 1/2. P. 18. 



The length of the head is two-sevenths of the total length (without caudal). The 

 teeth on the palate are in a single series, very short, obtuse, incisor-like. Pectoral 

 very large, extending backwards to the sixth anal ray. Head, body, and fins brown, 

 with a network of yellowish lines ; vertical and pectoral fins with a white margin. 



In other respects this species agrees with T. maculosa ; so that we may refer to the 

 description of that species given above. 



Three specimens were found by Messrs. Dow and Salvin on the Pacific coast of 

 Panama; the largest is 13 inches long. 



In this species I first observed and closely examined the poison-organ with which 

 the fishes of this genus are provided. Its structure is as follows : — 



1. The opercular part. — The operculum is very narrow, vertically styliform, and very 

 mobile; it is armed behind with a spine, 8 lines long in a specimen of 10|^ inches, and 

 of the same form as the venom-fang of a snake ; it is, however, somewhat less curved, 

 being only slightly bent upwards; it has a longish slit at the outer side of its extremity, 

 which leads into a canal perfectly closed, and running along the whole length of its 



Fig. 1. Hinder half of the head, with the 

 venom-sac of the opercular apparatus in 

 situ. * Place where the small openinj; 

 in the sac has been obseiTed. a. La- 

 teral line and its branches, b. Gill- 

 opening, c. Ventral fin. d. Base of 

 pectoral fin. e. Base of dorsal fin. 



Fig. 2. Operculum, with the perforated 

 spine. 



interior ; a bristle introduced into the canal reappears through another opening at the 



