T(I,\I)-1-IS1IKS. 



Fam BATRACHIDiE. 



Bodji tadpole-sliapcd, posterlarli/ coiitjin'a.'icd, (luterioiiy terete witit Ijroad, Jtut head. Scales small and cycloid. 

 Eyes small, and directed more or less upwards. First dorsal fin short, -with strong spinous rays; second dorsal 

 long; anal similar in form to the second dorsal, hut sJiorter. Basal Ijones of tJie pectoral fin flat in the external 

 {distal) part, hut elongated, and anteriorli/ (in the proximal jiart) narrow". Jaw-teeth of uniform size and pointed, 

 set in a card, or some of thou larger and ohtuse. Vomer and palatine hones also furnished with numerous teeth. 

 Lips fringed. Lateral line continuous or hrokeii : the rest of the system of the lateral line and of the muciferous 

 ducts liighly developed. Only three perfect branchial arches. (Ull-openings confined to the sides in front of the 

 pectoral fins. No pseudohranchia}. Air-hladder more or less completely divided in a longitudinal direction, or 



hrohen up into two rhamJiers with a communication between them. 



By the broad, flattened liead and the loose, slippery 

 skill, which is covered witli extremely small scales or 

 even naked, these fishes are [ilai'ed in aliout the same 

 relation to the Weevers as the Cottoids to the Scor- 

 pajnoids. We have fnrther proof that the natural place 

 of the Batrachoids in the system is by the side of the 

 Weevers, not only in the arrangement of the fins and 

 the otlier characters given above. Both tliese families 

 have another common peculiarity in the poison organs 

 wliicli they possess. Gunther'' has described these or- 

 gans in tlie genus Thalassophryne from Central America, 

 which belongs to this family. They are situated, as 

 in the Weever, on the operculum and in the spinous 

 rays of the first dorsal tin, but are still more highly 

 developed. The opercular spine is perforated, like the 

 fangs of the true vipers, and not merely grooved, as 

 in the Weever, the spines of which in this respect re- I 

 seml)le the fangs of venomous colubrine snakes. 



By the side of this poison organ in some Batra- 

 choids is another, which, hoAvever, belongs rather to 

 the system of the lateral line and of the muciferous 

 ducts, and the venomous pi'operties of which are not 

 yet fully demonstrated. The advanced development of 

 the system of the lateral line is not confined to the : 

 head, with the usual, but numerous, branches, especially 

 in the suborbital ring, where there is sometimes a row 

 of pores hidden under a peculiar, longitudinal, dermal 

 flap; but also extends to the trunk. This appears most 

 distint'tly in the genus Porichthys, from both the east 



and the west coasts of America, in which the poi-es of 

 the lateral line, at least during youth, are especially 

 distinguished by a golden-yellow, cornea-like substance 

 in tlie openings. In this species the branches of the 

 lateral line run, as usual, in graceful curves on the 

 head and the middle of the sides, but also on the 

 operculum and the branchiostegal membrane, as well 

 as on the lower side of the lower jaw and on the 

 belly itself, in curves which surround the ventral fins, 

 ascend on the anterior side of the lobate base of the 

 broad, pectoral fins, and surround tlie vent. Another 

 branch slopes down from the axil to the lower part of 

 the side, and then follows the base of the anal fin for 

 some distance. Another branch of the lateral line, 

 a dorsal canal, runs close to the base of the second 

 dorsal fin. In the genus Batrachus, on the back of 

 the pectoral fins, we find a row of pores from which 

 oozes a slimv moisture, and in the axil of these fishes 

 is a cavity beneath the skin, which in some species 

 opens into a liole in the corner of the shoulder. The 

 properties of the secretion formed in this cavity are 

 not yet known; but Guntheh" endeavours to explain 

 it by a comparison with a similar structure in the same 

 part of the body in certain Siluroids, where the poisonous 

 properties of the secretion are more probable, as it is 

 emitted at the base of the defensive weapons these fishes 

 possess in the strong, serrated spines of the pectoral fins. 

 The ventral fins of the Batrachoids are remarkable 

 not only for their jugular position, but also for their 



" In Batrachus Facifici, the only spuoies the skeleton of which I have been enabled to examine, I find 5 basal bones belonging to the 

 pectoral fins, or one in excess of the ordinary number. The uppermost is narrow and terete, and has no rays of the pectoral fin articulating 

 with it. The 3rd and 4th from the top are considerably narrower than the rest. The lowest of all is the largest and broadest. 



'' Proc. Zool. Soc. 18G4, p. 155. 



' Introd. to Stud;/ of Fi.'ih, p. 102; Handb. Ic/ilhi/oL, p. 120. 



