486 PISCESSUB-CLASS III.—TELEOSTOML 



is very large. In habits these fish are carnivorous, some of them being pro- 

 vided witli powerful incisor teetli, for the purpose of feeding on coral. 



More familiar than the last is the extensive and important family of the 

 wrasses, or thick-lipped fishes, in which the scales have smooth margins 

 (cycloid), and the pouting lips are often greatly thickened. 

 Family Lahridm. As in the preceding family, the dorsal fin is single, with the 

 spiny portion at least as well developed as the rayed, which 

 is similar to the anal ; and the pelvic pair are thoracic in position, and com- 

 prise five rays and a single spine. Whereas in some of the wrasses the body 



is deep, in others it is of a more 

 elongated shape. Wrasses are coast 

 fishes, mostly of carnivorous habits, 

 which attain their maximum de- 

 velopment in the tropical and 

 temperate seas. Although their 

 palates are unarmed, their jaws are 

 Fig. 17.— SiEipED Wkasse. provided with a number of powerful 



teeth admirably suited for crushing 

 the shell-fish on which these fishes chiefly subsist. Sea-anemones or corals 

 afford, however, a preferable diet to some of the species, while a few are 

 strict vegetarians. Wrasses are divided into a number of genera, which may 

 be arranged in larger groups in correspondence with the conformation of the 

 front teeth. In the typical Lahrax, of which the headquarters is the Medi- 

 terranean, the jaw-teeth are conical and arranged in a single series. The two 

 Bx'itish forms are the ballan (L. mcMidatus) and the striped wrasse {L. 

 mixtus), of which the latter exhibits great sexual differences in coloration. 

 The gold siimy represents in Britain a genus {Orenilahrus) differing from the 

 true wrasses in having the edge of the preopercular bone serrated at all ages, 

 instead of only in the young. 



Passing by many other types, brief reference must be made to the parrot- 

 wrasses [Scarus), deriving their name from the confluence of the anterior 

 teeth to form a cutting beak. One species is common in the 

 Family Mediterranean, where it was well known to the ancients. 



Diatrematidm. The viviparous wrasses (Ditrema and Heterocarpus) are note- 

 worthy on account of their peculiar reproduction, and are 

 accordingly referred to as a family by themselves. These fishes, which do not 

 attain to a large size, are very characteristic of the temperate portions of the 

 North Pacific, where the majority of the species are confined to the American 

 side, although a few occur on the Asiatic. 



The last group of the Acanthopterygii is the somewhat important family 

 of the chromids, wliich have a very remarkable geographical distribu- 

 tion. From the other members of the group with the lower 

 Family pharyngal bones united, they are distinguished by being 



Chromidida:. exclusively fresh-water in their habitat. Although none of 

 the genera inhabiting the Eiistern Hemisphere are common 

 to the Western, these fish inhabit the rivers of Tropical Africa, Madagascar, 

 Syria, Palestine, and Tropical America, while a single genus is found in 

 India. From the other members of the present group, the Chromids may be 

 distinguished by the absence of false gills. In appearance they are not very 

 unlike wrasses, having a single dorsal fin, of which the anterior portion is 

 spiny, the scales generally ctenoid, and the lateral line more or less markedly 

 interrupted. In regard to diet, they display considerable variation, some 



