44S 



TELEOSTEI 



Family Gobiidae. The dorsal fin has a separate soft hinder portion ; 

 the anterior portion is supported by flexible spines, and may be reduced. 

 The dentition and sealing varies; the scales may be smooth, ctenoid, 01 

 absent. There is no lateral line, and usually a large anal papilla. 



Periophthalmus is modified for progression on land, and has powerful 

 pectoral fins, and protruding eyes brought up on to the top of the head. 

 Fossil tonus have not yet been determined with certainty. Marine and 

 freshwater, widely distributed. 



Gobius, Ait.: widely distributed. Elcotris, Gron. ; freshwater, tropics. 

 Benthophilus, Eisch. ; Caspian. Periophthalmw, Schn. ; tropics. 



Tribe 3. Echexeidiformes (Discocephali). 



Distinguished by the extraordinary modification of the separate 

 anterior dorsal fin, which extends on to the head as far as the snout, and 

 becomes flattened out into an oval sucking disc with transverse ridges, 



Fig. 404. 

 Rernora brachyptera, Lowe. (From Jordan and EvermaBn.) 



strengthened by a double series of serrated plates seemingly the modified 

 lepidotriehia (Figs. 464-5) (Storms [427]). The skull is correspondingly 

 flattened, its bones are deeply sunk and smooth, and there is no eye-muscle 



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Fig. 465. 

 Sucking disc rachyptera, Lowe. Dorsal view. (From Jordan and Evermann.) 



canal. The supraclavicle is reduced. The scapula perforate, and three 

 radials rest on the coracoid. Already in the Eocene fully differentiated 

 representatives of this family are found. It appears to have no close 

 affinity to the Sconibriformes, with which it was long associated. 



