598 CONTRIBUTIONS TO NOETH AMERICAN ICHTHYOLOGY IV. 



terminal; premaxillaries protractile; maxillaries without supplemental 

 bone, slipping under the membranaceous edge of preorbital; the anterior 

 teeth in the jaws usually very strong ; teeth of the jaws separate or 

 more or less soldered together, sometimes forming a continuous plate; 

 DO teeth on vomer or palatines ; lower pharyngeals completely united 

 into one bone, without median suture. Lij)s thick, longitudinally pli- 

 cate. Nostrils round, with two openings on each side. Dorsal fin con- 

 tinuous, the spinous portion long; anal similar to soft dorsal, usually 

 with two or three spines. Ventrals thoracic, I, 5. Branchiostegals 

 5- '5. Pseudobranchiae present. Gills 3 J ; the slit behind the last arch 

 small or obsolete; the gill-membranes somewhat connected, often joined 

 to the narrow isthmus. Air-bladder present. No pyloric coeca. Genera 

 65, species 450, chiefly of the tropical seas. Many of them are brilliautly 

 colored, and some are valued as food-fish. Most of them feed uj)on mol- 

 lusks, the dentition being adapted for crushing shells. The group has 

 been much subdivided, and many of the current genera are distinguished 

 by characters of little importance. 



{Labridce Giinther, iv, 65-244.) 

 a. Teeth in jaws distinct; pharyngeal teetli not coufluent; anal spines 3. 



h. Dorsal fiu with 15-20 sijiues; teeth all coiiical; no i)osterior cauiues; lateral line 

 continnous. {Ldbrince.) 

 c. Preopercle serrate ; cheeks and opercles scaly ; teeth in a band, the outer en- 

 larged Ctenolabkus, 315. 



cc. Preopercle entire ; cheeks scaly; opercles naked ; teeth in about two series. 



Tautoga, 316. 

 ccc. Preopercle entire; cheeks and opercles scaly; teeth iu a single series. 



Lacilnol^mus, 317. 

 hh. Dorsal fin with 8-13 spines. {Julidince.) 

 d. Lateral line continuous. 

 e. Cheeks and opercles scalj"^'; dorsal spines 12 ; posterior canines present. 



Harpe, 318. 

 ee. Cheeks and opercles naked or very nearly so ; dorsal spines 9. 



/. Posterior canines well developed Platyglossus, 319. 



//. Posterior canines obsolete Pseudojulis, 320. 



dd. Lateral line interrupted; head naked, its upper edge usually trenchant. 



Xyrichthys, 321. 

 ca. Teeth in jaws confluent; pharyngeal teeth jiavement-like ; anal spines 2; scales 

 large. (ScarincB.) ** 



g. Teeth partly separate, the anterior distinct; dorsal spines flexible. 



Cai.modon, 322. 



gg. Teeth soldered together, forming a plate like the jaw of Tetrodon; 



each jaw divided on the median line ; dorsal sjiines flexible ; scales 



on cheeks in two or more rows Hemistoma, 323. 



