6. SCATOPHAGUS. 57 



D. Young specimens with small scales, sometimes with larger ones 

 between the smaller ones. Coloration like the former : Pomacanthvs 

 arcuatus. 



w, X. Skins. Jamaica. From Dr. Parnell's Collection. 



y. Stuffed. 



2. Purchased of Mr. Frank. 



Skeleton. — The structure of the skeleton agrees in the chief points 

 with that of Chcetodon. The maxillary bone is very short, and may 

 be almost entirely hidden below the praeorbital ; it is crossed by a 

 long horizontal process arising from the palatine bone. The inter- 

 maxillary has the posterior process very elongate, and the descending 

 branch exceedingly short. The articular and dentaiy of the man- 

 dibula are well developed and somewhat oblong. The limbs of the 

 prgeoperculum form together a nearly right angle, and are not den- 

 ticulated : the lower limb is one-half the length of the posterior ; 

 the interior ridge is very depressed, and there is scarcely a trace of a 

 muciferous channel ; the operculum is subquadrangular, with the 

 posterior side slightly concave ; the suboperculum is lanceolate ; the 

 interoperculum broader anteriorly than posteriorly. The pra3orbital 

 is oblong, and rather broader than the inferior portion of the subor- 

 bital ring, the posterior being firmly attached to the praeoperculum ; 

 there is a concave plate at the inner side of the suborbitals, to sup- 

 port the eyeball from beneath. The turbinal bones are elongate, and 

 in immediate contact with each other posteriorly, where they are 

 broadest. The anterior frontal bones are small, and overreached by 

 a slight prominence of the principal frontals. The bones of the 

 crown of the skuU form one smooth, rounded and veiy elevated mass, 

 terminating above in an exceedingly high and strong occipital crest, 

 to the upper end of which are joined the processes of two spurioiis 

 interneural spines. Of the sutures, those between the frontals and 

 the supraoccipital are visible. The sujjrascapula is entirely united 

 with the bones of the skull ; the humeral is strong, sword-shaped. 

 The radius and the coracoid form a broad shallow ca\ity for the 

 muscles of the pectoral fin ; both bones are partly separated from 

 each other by a cleft and by an ovate open space. Each pubic bone 

 is composed of three lamellae of nearly equal development. 



There are ten abdominal and fourteen caudal vertebra;. The an- 

 terior interneural and neural spines are dilated posteriorly in a trans- 

 parent lamella. The two anterior haemals are grown together, but 

 the corresponding interhtemals are free. 



6. SCATOPHAGUS*. 



Scatophagus, Ctiv. S^- Val. vii. p. loO. 

 Cacodoxus, Cant. Catnl. p. 168. 



Body much compressed and elevated. Snout of moderate length. 

 Two dorsals, united at the base, the fii'st with ten or eleven spines, 



* 1. Scatophagus purpurascens, Cuv.^ Val. vii. p. 14'1. — East Inclies. 



