ELEOTKIS. 537 



gobiid^;. 



Mouth protractile, the maxillaries excluded from the oral border. Lower pharyngeal 

 bones separate. Two nostrils on each side. Suborbital arch ligamentous or absent. 

 Gill-membranes more or less broadly attached to isthmus ; gills four, a slit behind the 

 fourth. Scapula and coracoid more or less reduced or even vestigial ; pterygials large, 

 4 or 5 in number, forming together a thin plate which is in contact with or narrowly 

 separated from the clavicle ; one or two of the pterygials in contact with the coracoid. 

 Ventral fins thoracic, with a feeble spine and four or five soft rays, sometimes united 

 to form a sucking-disk. Usually two distinct dorsal fins, the first formed of slender, 

 flexible, non-articulated, simple rays, the second similar to the anal. All or most of 

 the prsecaudal vertebrae with transverse processes bearing the ribs. Air-bladder often 

 absent. 



A large, almost cosmopolitan family of carnivorous fishes, mostly inhabitants of the 

 sea or brackish waters, or occurring in both salt and fresh water. The genus Uleotris, 

 with which we have to deal here, consists principally of freshwater species. It may 

 be regarded as the most generalized type of the Gobiidae, which include such remarkably 

 aberrant forms as the Walking-fish or Jumping-fish, Periophthalmus, so common at the 

 mouths of tropical African rivers. 



1. ELEOTBJS. 



Gronovius, Zoophyl. p. 83, part. (1781) ; Giinther, Cat. Fish. iii. p. 105 (1861). 



Body moderately elongate, covered with ctenoid scales. No lateral line. Teeth 

 small. Two dorsal fins, the anterior with 5 to 8 rays. Ventral fins distinct. Air- 

 bladder present. 



This genus includes close upon a hundred species, mostly from the Tropics. Fourteen 

 species are known from the fresh waters of Africa. Until Mr. Loat's discovery of 

 the species here described, no Gobiids were known from the Nile. 



3z 



