28 



The following genera] characters assigned to Glaucosoma 



lor the present, may be amended when the structure of the 



fish shall be more fully ascertained. 



Aspectus scicenoideus. Circumscriptio lateralis oblongo- 

 elliptica. 



Caput satis viagmim, ohtusiusculum, fere totum squamo- 

 sum. Labia membranaeque branchiostegoi laves. Os 

 modicum. Fori nulli in maxillA inferiori. 



Dentes breres, carminiformes ; exteriores intermaxilla- 

 riutn et interiores maxillcB inferioris pauld majores. 

 Dentes vomeris et palati conformes sed adhuc minores. 

 Dentes pltaryngis paviti ? 



Oculi fnajusculi later ales, ante medium caput. 



Nares oculis approximate, aperturis magnis rotundis 

 contiguis. 



Os preorbitale subgrande genam asquans, margine integer- 

 rimo. Preoperculum obtuse curvatum, crenulatum. 

 Suboperculum margine concavum. Operculum obtu- 

 sissimum apicibus osseis duobus plants, obtusis, vix 

 conspicuis. Scapula semi-rotundata squamosa, cre- 

 tiulata. 



Squamae corporis majusculm ctenoidea minutissime stri- 

 ata : rostri et verticis parva; maxillce et gence majores; 

 operculi interoperculiqve adhuc majores, nee tumen 

 squamas corporis cequantes. 



Linea lateralis fere recta. 



Pinnae pectorales parrce. Pinnae ventrales sub axillis pin- 

 naruni pectoralium positic. Pinna dorsalis lurica ; 

 sjiincB rudiis arlicularibus breviores : pars articutaris 

 ejus pinnrnque ani ad basin squamosa. Membrana 

 branchiostega radiis septem vel interdum octo sustentata. 



The profile of Glaucosoma hebraicum is bounded above 

 and below bj- nearly similar segments of a Hat elliptical 

 curve which meet in a bluntish apex at the mouth. 

 These curves are lost posteriorly in the trunk of the tail. 

 The greatest height of the body is just behind the ven- 

 trals, and equals a third of the entire length, caudal in- 

 cluded. The height of the trunk of the tail again, where 

 narrowest, is a third of that of the body, and its length is 

 considerable, forming behind the dorsal nearly a fifth of 

 the whole length, but behind the anal scarcely a sixth. 



The length of the head and its height at the nape are 

 about equal, and are contained upwards of three times in 

 the length of the fish. The opening of the mouth scarcely 

 extends backwards to beneath the nostrils, and it descends 

 nearly at an angle of 45° when closed, its apex then being 

 on a level with the middle height of the head and body. 

 The maxillary, which is densely scaly, dilates gradually 

 to its wide and truncated lower end. Its lower corner 

 reaches to beneath the posterior third of the eye. The 

 intermaxillaiies are but slightly protractile, and the lower 

 jaw, when depressed, projects beyond them. The dental 



forwards, as in some species of Perco-labrax or Plectropoma, and lis spi- 

 nous dorsal is l)oldly arclied, forming a deep notch al tlie origin of tlie 

 jointed jiart, so that it might with m^re propriety be rauged with Perca 

 or Perco-labrax than left in Centropristes. Aulacorephalus is a Japanese 

 lormwliich alsowould technically] all into Centropristes, bulwhich Messrs. 

 Teniminck and Schlegel have kept separate ou account of its dissimilar 

 aspect. It has a strong resemblance to Serratms or Plectropoma. 



surface is broadest towards the apex of the jaws, narrows 

 at the corners of the mouth, and is interrupted by a nar- 

 row smooth space at the symphyses above and below. 

 The dentition may be described as card-like, the indivi- 

 dual teeth being subulate, curved backwards, and short, the 

 exterior rows above and the interior ones below being just 

 perceptibly larger. On the limbs of the jaws the dental 

 surface is about five teeth wide above, and three or four 

 below. A narrow velum exists in both jaws. The vome- 

 rine and palatine teeth are more minute, but otherwise 

 similar. The palatine teeth form a very narrow band on 

 the edge of the bone. 



The nostrils are two round contiguous openings on each 

 side, situated close before the eye in a narrow membranous 

 space. The posterior opening is the largest, and is of con- 

 siderable size. 



The large, round eye is situated high on the cheek, 

 but does not touch on the profile, the frontal region 

 above it being convex both transversely and longitudinally. 

 The preorbitar is well developed, having a vertical height 

 equal to the diameter of the orbit, and a length two and a 

 half times greater. It is densely scaly, and is ou a level 

 with the cheek, so that its posterior boundary cannot be 

 defined. Its anterior edge is thin, curved with a slight 

 convexity, entire and slightly free, but does not cover more 

 than the mere edge of the maxillary. The space at the 

 corner of the mouth, over which the limb of the maxillary 

 passes, is smooth and scaleless. The scales of the cheek 

 advance to the edge of the orbit, and completely conceal 

 the suborbitar chain ; and they extend over the temples to 

 the side of the head, and cover the disk of the preopercu- 

 lum, without any change in their character. 



The preoperculum has its upper limb slightly inclined 

 forwards, and is greatly rounded off at the corner, the curve 

 extending to the whole under limb, which is shorter than 

 the upper one. A very shallow notch at the corner is 

 filled with membrane, the upper limb is minutely serrated, 

 and the lower one finely gnawed, or irregularly crenated. 

 Fine streaks appear obscurely among the scales which end 

 irregularly close to the edge of the bone.* 



The interoperculum is entire on the edge, and covered on 

 the surface with scales larger than those of the cheek. 

 Near its articulation with the lower jaw it is edged by a 

 slip of membrane, on which the scales are much smaller. 

 At its junction with the suboperculum, opposite to the 

 notch of the preoperculum, and in the usual site of the 

 knob of Diacope, it swells up slightly. The under edge of 

 the suboperculum is curved like a reversed italic /, which 

 produces a lobe anteriorly, that is wider than the interoper- 

 culum, and has its margin finely streaked or plaited. This 

 bone has precisely the same shape in Glaucosoma biir- 

 geri. The bony operculum ends in two flat, thin, obtuse, 

 striated tips, which are almost lost among the scales, and 

 are separated by a deep angular notch. This notch is 

 concealed by scales, and the membrane which edges the 

 bone is covered with small scales, the posterior edge of the 

 gill- cover being very obtuse. Above the upjrer angle of 

 the gill-opening the scapular bone exists with a iiee, 



* This bone makes no approach in form to that of Lobotes, in wliich 

 the preoperculum has an angular, serrated, projecting corner. 



