1. OPniOCEPHAT.US. 481 



Grejish-olivc (in spirits), with two series of large roiind brown spots 

 incompletely edged with silvery. Irregular spots on the upper sur- 

 face of the head ; a brown band from the eye, continued into the 

 upper series of spots ; another, which is interrupted, from the eye to 

 the base of the pectoral. 

 Fresh waters of China. 



This species is closely allied to 0. argits, but maybe readily distin- 

 guished by the larger scales and smaller number of fin-rays. 



a, b. Adult. China. Presented by J. R. Reeves, Esq. — One of these 

 specimens has the body lower than the others, its depth being 

 one-eighth of the total length. 



c, d, e-f. Adult, half-grown, and young. China. 



g. Adult : skeleton. 



A. Intestines of specimen g. 



The stomach is an oblong csecal cavity ; there are two pyloric ap- 

 pendages, the length of each being two-fifths of that of the intestines ; 

 the latter make an inferior and superior curve, and are half as long 

 as the fish. The liver has two notches, the left lobe being somewhat 

 prolonged downwards. Gall-bladder free. The air-bladder is simple, 

 exceedingly long, extending on between the muscles of the tail to 

 the end of the anal fin. 



Sheleton. — The skull has some resemblance to that of a Mugil ; its 

 upper surface is flat and smooth, the interorbital space broad ; there 

 is no occipital crest, and scarcely any on the sides. The principal 

 frontal bones extend on to the anterior part of the orbit, where they 

 are continued by the tui'binal bones, which are well ossified and form 

 oblique sutures with the frontals. The postfrontals are narrow, 

 situated at the side of the principal frontals, and form a ridge pro- 

 jecting over the tympanic groove. Praefrontals small ; a narrow 

 portion of the ethmoid is visible between the turbinal bones. The 

 bones of the jaws are strong, elongate ; the maxillarj' slightly di- 

 lated posteriorly ; processes of the intermaxiUaries short. The head 

 of the vomer is semicii'cular ; palatines long ; infraorbital ring com- 

 plete, of moderate •nadth ; tympanic groove very large, with the bones 

 well ossified ; the limbs of the praeoperculum meet at a right angle, 

 and are of equal length. The epitympanic has a broad vertical 

 lamella interiorly, which forms a part of the cavity accessory to the 

 gill-cavity ; the upper and lower pharjTigeals are covered with cardi- 

 form teeth, and do not show any peculiarity in their form. 



The system of muciferous channels is well developed, and received 

 into the interior of the bones ; very distinct pores indicate their 

 course. One of the channels commences on the turbinal bone, and 

 is divided into two portions, one of which rans along the infra- 

 orbital ling, the other along the frontals ; a transverse branch unites 

 the frontal portion with that of the other side. The infraorbital and 

 frontal portions are confluent into one branch behind the orbit, ninnuig 

 along the postfrontal and parietal to the upper end of the praeoper- 

 culum. The second chamiel commences at the symphj'sis of the 



VOL. III. 2 1 



