DR. GtJNTHER ON THE FISHES OF CFJMTRAL AMERICA. 



4:57 



lines. 



Total length 54 



I-ength of the head 10 



Width of the head 14 



Depth of the head 10 



Diameter of the eye 1 



Length of the caudal fin iS 



of the ventral fin 7 



93. THALASSOrHRYNE RETICULATA. (Plate LXVIII. fig. 2.) 

 (iuuth. Proc. Zool. Soc. 1864, pp. 150, 155. 



D. 2|24. A. 24. V. 1 '2. P. 16. 



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 tliat 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 fii-st observed and closely examined the poison-organ with wliich 

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



1. Tlie opercular ])aTt- — The operculum is very narrow, vertically styliform, and ver\ 

 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, 

 wliich leads into a canal perfectly closed, and running along the wliole length of its 



Fig. 1. Hindt'i- hall' of the hoad, with the 

 venom-sac of the opercular apparatus in 

 situ.. * Place where the small openin<r 

 in the sac has been obsciTpd. n. La- 

 teral line and its branches, h. tiill- 

 opening. c. Ventral fin. d. Base of 

 pectoral tin. e. Base of doi-sal fin. 



Fig. 2. Operculum, with the perforated 

 spine. 



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



