FROG-FISHES. 179 



the British Isles, and on the northern shores of 

 Europe. 



Genus Lophius. (Linn.) 



The head in this genus is enormously large 

 in proportion to the body, very broad, depressed, 

 and spinous in many parts ; the mouth is wide, 

 deeply cleft, armed with teeth, differing in size, 

 but numerous, sharp and incurved ; the lower 

 jaw fringed round with a series of free fleshy fila- 

 ments. The tongue is broad; the gill-cavities 

 are capacious, but open by a small aperture ; the 

 gill-rays are six in number. There are two dor- 

 sals, separated ; the summit of the head is fur- 

 nished with two or three bony filaments, jointed 

 in a peculiar way to the skull, so as to be capable 

 of free motion in various directions. Cuvier con- 

 siders these as being, structurally, the first spines 

 of the anterior dorsal. '' In the Angler, or Fish- 

 ing-frog {Lophius piscatorius, Linn.) of the Bri- 

 tish seas, the motions of these detached rays are 

 very peculiar. Two are considerably in advance 

 of the eyes, almost close to the upper lip ; the 

 posterior of these is articulated by a stirrup upon 

 the ridge of the base, but the anterior one is 

 articulated by a ring at its base, into a solid staple 

 of the bone, thus admitting of free motion in 

 every direction, without the possibility of dis- 

 placement, except in case of absolute fracture. 

 The third one, which is on the top of the cra- 

 nium, behind the eyes, is articulated much in the 

 same manner as the posterior one of the other 

 two ; and of course, though these two have con- 

 siderable motion in the mesial plane of the fish. 



