FISHES. 257 



The species are mostly of small and even minute size, but a few reach moderate 

 dimensions — between one and two feet. Some are quite peculiar for their habits. 



On the Californian coast is a Gobiid ( Gillichthys mirabilis) remarkable for the 

 great extension backward of the jaws and singular habits. It chiefly lives in shal- 

 low places, left bare at low tide, and harbors in holes excavated by itself in the mud. 

 Numbers are obtained, especially by the Chinamen, by digging. It is thought to taste 

 somewhat " like eels." 



Certain other species belonging to the genus Periophthalmus have large protuber- 

 ant eyes and pectoral fins capable of being flexed downwards and forwards, and usable 

 as legs. They frequent mud flats and coasts, and at low tide are left out of water, 

 and progress then by regularly hojjping, their fore fins or pectorals assuming the func- 

 tion of the hind limbs of kangaroos and other leaping mammals ; they are assisted, 

 howe\'er, by the tail. The prominent eyes, to which reference has been made, and 

 which are very versatile, come into use for observation in different directions. This 

 ability to progress on land enables them to pursue beach crustaceans as well as 

 insects, and another object of pursuit is* a slug-like gastropod named Onchidium. 

 The species are confined to the coasts of the Indian oceans and western Africa. One 

 of the most common is the Periophthahnus koelreuteri. Two or three closely related 

 genera share their range in whole or part. 



Other families generally associated with the Gobiidre are Oxudeecid^, Calliony- 

 MID.J;, and Platypterid^. The Callionymidse have the ventrals very far apart, a 

 large preopercular spine, and very restricted gill-openings. The species, between 

 thirty and forty, are mostly tropical, but one occurs along the British coasts, and is 

 known as the dragonet or sculpin. 



Still more aberrant fishes are now to be seen. They are numerous and diversified 

 — so much so that not less than eleven families have been recognized for them, — but 

 they may all be provisionally retained in the superfamily BLENNIOIDEA. 



In appearance, at least, the least abernant of the series are the Clinidjs. These 

 have a moderately long or oblong body, and regular scales cover it ; the head rather 

 projects forwards, the dorsal has a very long spinous portion (the spines are stiff) and 

 a shorter soft one, and jugular ventrals with a spine and two or three rays are 

 developed. Of all the fishes which have already been treated of, the Chiridse appear 

 to be those to which they are most nearly related, and they may have sprung from a 

 common stem, the Chiridas being less and the Clinidse much more modified. 



The Clinidse are mainly inhabitants of the tropical and subtropical seas, although 

 several reach the coast of the United States, and one of the Largest of the family — 

 Jleterostichus rostratus — occurs along the Californian slojie. 



The Blenniid^ are also oblong or moderately elongated fishes, but with a naked 

 skin ; head more or less shortened or blunt ; teeth movable in front ; the dorsal with 

 nearly equal inarticulate and articulate portions ; the " spines " slender and flexible, 

 and the jugular ventrals with the spine concealed or atrophied, and two or three 

 thickened rays. The species are very numerous, although only about nine are to be 

 found along the American coasts, most being inhabitants of tropical seas. 



Some of the most remarkable of the Blennii<ls are those of the genus Salarias, 

 and, as the generic name implies, they can lea2> sometimes many times their own 

 length. 



The largest of the Blennioid group are the formidalile wolf-fishes, constituting the 

 family Anarrhichadidjj. These have an oblong but robust body, with rudimentary 



VOL. III. — 17 



