106 NORTHERN ZOOLOGY. 



LABROIDEvE. 



The fish of this family are readily recognisable by their general aspect, their 

 oblong scaly body, and single dorsal, whose anterior rays are spinous, with often 

 a shred of membrane attached to them. Their pharyngeal bones are armed 

 with teeth stronger than usual, but varying in form in the different genera. They 

 have a strong air-bladder, and either no caeca or only two very small ones. The 

 Linnaean genus Labrus forms a group which is distinguished by having one set of 

 lips attached to the snb-orbitars, and another to the jaws, close gill-membranes 

 supported by five rays, conical jaAV teeth, the anterior and middle ones longest, and 

 pharyngeal teeth in form of paving stones. The minor groups are characterised by 

 combinations of several varieties of structure, such as the smoothness or scaliness 

 of the head, the presence of denticulations on the preoperculum, the protractility of 

 the mouth, which, in several sub-genera, can be projected in a tubular form, so as 

 to seize small fish that are swimming within its reach, the straight or broken 

 lateral line, the encroachment of the scales on the caudal, or even on the other 

 vertical fins, as in the Cheetodontoidese, the prolongation of the first dorsal rays by" 

 long filaments, and some differences in the dentition. In the sub-genus Anampses 

 the jaws are armed with only two flat teeth, which project from the mouth and 

 curve outwards. The genus Xirichthys differs from Labrus chiefly in its very 

 compressed form and the vertical profile of the head : it has large scales and an 

 interrupted lateral line. Chromis resembles Labrus except in the jaw and pharyn- 

 geal teeth being in card-like plates, the vertical fins filamentous, and the lateral 

 line interrupted. Cychla has all the teeth like velvet pile and in broad stripes. 

 Ples'wps differs from Chromis in having a compressed head and very long ventrals. 

 MalacantJms, with the general characters and jaw teeth of Labrus, has the pharyn- 

 geal teeth of Chromis, the operculum ending in a small spine, and a long dorsal in 

 which the spines are very lew, slender, and flexible. Scarus is remarkable for 

 convex jaws covered anteriorly and on their edges with teeth like scales. The 

 pharyngeal teeth are in transverse plates, the sub-orbitar lips of the preceding 

 genera are wanting, there being only those on the jaws, the scales are large and 

 the lateral line interrupted. Calliodon and Odax, with some of the characters of 

 Scarus, have others more closely resembling Labrus. 



Many of the Labroidese are remarkable for the intensity and purity, as well as 



