408 SPINY-FINNED GROUP. 



numerous than in the tropics. Among the numerous genera we can only mention 

 the typical Gobioesox, from the West Indies and Pacific coast of South America, 

 distinguished by the absence of a front free margin to the posterior division of 

 the sucker, and the presence of incisor-like teeth at least in the lower jaw; and 

 the European Lepadogaster, in which the hinder-half of the sucker has an anterior 

 free margin, and the teeth are small and fine. The British species, although 

 variable in this respect, are very prettily coloured ; the figured one being generally 

 carmine-red above, and pale flesh-colour below, with a light patch between the 

 eyes, and two more or less distinct spots on the sides. It has been obtained 

 adhering to stones and shells in deep water off Torquay. Montagu writes that 

 when placed in a vessel of sea- water these little fish <: always adhered to the sides of 

 the glass by the apparatus termed the sucker, and frequently remain fixed till they 

 died ; and even after death the power of adhesion continues. The wet finger being 

 applied to the part, the fish becomes suspended ; when alive, they instantly attach 

 themselves to the hand if taken out of the water." 



The Serpent-Heads, — Family Ophiocephalidje. 



Mainly characteristic of the Oriental region, although also represented in 

 Africa, the fresh-water fishes known as serpent-heads are interesting not only 

 on account of their structure, but likewise from their peculiar habits. They form 

 a single family, constituting a sectional group by itself, and represented by two 

 genera, in one of which (Ophiocephalus) pelvic fins are present, while in the 

 second (Channa) they are wanting. As a family, the serpent-heads are character- 

 ised as follows. The body is elongate and covered with medium-sized scales ; all 

 the fins are devoid of spines, the anal and single dorsal being long and low ; and 

 there is an additional cavity above the proper gill-chamber, although this is not 

 furnished with supplemental gills. The depressed head is covered with somewhat 

 plate-like scales, and has the eyes lateral and the gill-openings wide ; each gill- 

 chamber containing four gills, while teeth are present on the jaws, palatines, and 

 vomer. If present, the pelvic fins are thoracic in position, and composed of six 

 rays. The lateral line is sharply curved or almost interrupted, and an air-bladder 

 is present. Of the typical genus there are some thirty existing species, having 

 a distribution coextensive with that of the family, and in Asia ranging over 

 Baluchistan, Afghanistan, India, Ceylon, Burma, China, Siam, and the Malay 

 Archipelago; the figured species (0. striatus) being common to such distant 

 localities as India and the Philippines, and at times reaching as much as a yard 

 in length. The second genus, Channa, is represented only by a single species from 

 Ceylon and China. In a fossil state these fishes have been identified from the 

 Pliocene rocks of the Siwalik Hills in North-Eastern India. 



In India the serpent-heads are found both in rivers, ponds, tanks, and swamps, 

 many of them seeming to prefer stagnant to running waters. Day writes that 

 these fishes " having hollow cavities in their heads, and an amphibious mode of 

 respiration, are able to exist for lengthened periods out of their native element, 

 and can travel some distance over the ground, especially when it is moist. They 

 are able to progress in a serpentine manner, chiefly by means of their pectoral 



