468 PISCES SUB-CLASS IILTELEOSTOML 



genera namely Myripristis and Holocentrum most or all of whose members 

 are found near the surface. Like other deep-sea forms, these fish have a wide 

 distribution in species. Among the numerous genera, the single small 

 Japanese species of Monocentris is remarkable on account of the large size of 

 the vertically elongated scales, which form a kind of protective cuirass to the 

 body ; the opercular bones being unarmed. Anoplogaster of the Atlantic may be 

 cited as a genus with a naked skin; whereas in the allied Trachichthys there are 

 minute scales, from which the lateral line stands out in great prominence, both 

 having the eye very large. In this genus, too, as well as in the typical Beryx, 

 the dorsal fin is single, but in Holocentrum and certain other genera it is double. 

 The small family of the Curtidce likewise represents a section by itself, dis- 

 tinguished by the possession of only a single dorsal fin, which is much inferior 

 in length to the many-rayed and elongated anal, and like- 

 Section Curti- wise by the absence of the structure known as the supra- 

 formes. Family branchial organ. This family includes the Indian Curtis and 

 Curtidce. the Oriental and Tropical Pacific Pemperis. In both these 

 fishes the body is oblong, narrowing rapidly towards the tail; 

 and, if present at all, the spines of the dorsal fin are very few. The body is 

 covered with small or medium-sized scales ; and minute teeth are developed 

 both in the jaws and on the bones of the palate. 



This section, also, includes only a single family, of which the three generic 



representatives Polynemus Pentanemus and Gale.oides are easily recognised 



by the presence of a number of long filaments arising from 



Section below the pectoral fins. There are two somewhat short 



Polynemiformes. dorsal fins, separated from one another by a considerable 



Family interval ; and mucus-producing canals are well developed in 



Polynemidce. the head. These fishes are well represented on tropical 



coasts, and also enter estuaries and even fresh waters. They 



generally prefer muddy water, where their exceedingly elongated pectoral 



filaments doubtless act as efficient feelers. 



The Mediterranean umbrine (Umbrina), the meagre (ScicziKi), and the 

 drum (Pogonias) of North America are three fairly well-known fishes, repre- 

 senting as many genera of the Scicenidce. As a section, the 

 Section Sciseni- group is distinguished by the great length of the soft dorsal 

 formes. Family fin, which exceeds to a greater or less extent both the spin- 

 ScicKnidce. ous dorsal and the anal in this respect. Whereas these 

 fishes resemble those of the last family in the development 

 of mucus canals in the head, they differ by the absence of elongated pectoral 

 filaments. In the skull there is no bony connection between the preoper- 



cular bone and the orbit ; and 

 the pelvic fins are situated thor- 

 acically, and furnished with one 

 spine and five soft rays. Inform, 

 the body is somewhat elongate 

 and compressed, and the scales 

 are of the ctenoid type, with the 

 lateral line continuous, and often 

 extending on to the tail-fin. The 

 mouth is terminal, and armed 

 Fig. 7. THE MEAGRE. with bands of small teeth, among 



which enlarged tusks may be in- 

 terspersed, but there are no teeth on the palate. The medium-sized eyes 



