45. TRIGLA. 209 



below the prominent edge of the praeorbital ; the maxillary reaches 

 nearly as far backwards as the mandibula, and becomes gradually 

 somewhat broader posteriorly. The intermaxillary is shorter, has a 

 flat and sharply projectmg prominence behind, and the posterior 

 processes very short. The mandibula is rather low. The vomer is 

 very broad and quite flat, the anterior edge, however, being some- 

 what elevated. The following bones, cuirassing the cheek, may be 

 distinguished : — 



a. The middle one is the largest, subquadrangular, extending 

 from the vicinity of the nostril to the interior edge of the prseoper- 

 culum, to which it is firmly joined. It does not enter the orbit, nor 

 does it reach to the lower margin of the infraorbital bones. Fine 

 granulated striae proceed from its centre in every direction, that 

 running towards the angle of the prseoperculum being more promi- 

 nent than the rest, and forming a slight ridge. 



h. An upper series is formed by two narrow bones, constituting 

 the inferior margin of the orbit. The posterior one is attached to 

 the prajoperculum. 



c. An inferior series is formed by three bones, constituting the 

 lower margin of the snout, below which the jaw-bones are hidden. 

 The anterior is the praeorbital, forming a suture posteriorly with the 

 middle bone, and projecting anteriorly far beyond the cleft of the 

 mouth. The two other bones gradually taper posteriorly, and the 

 posterior touches the prseoperculum. The structure of the striae of 

 these bones is the same as in T. r/urnardiis. 



The prasoperculum and operculum form one continuous plane with 

 the infraorbitals; the former has a slight ridge across the angle, 

 which is provided with an obtuse point ; it is obliquely situated, and 

 its lower limb is almost reduced to nothing. The operculum has a 

 distinct ridge, terminating in a powerful spine. There are two deep 

 notches above this spine, separated from each other by a slender pro- 

 jecting point. The sub- and interoperculum are narrow and smooth. 



The ethmoid is large, pentagonal, 1| as long as broad, and sepa- 

 rates the turbinal bone from its fellow; the latter is weU developed, 

 irregularly shaped. The praefrontal is exceedingly large, and forms 

 a long suture with that of the other side ; it is armed with a spine 

 above the orbit, the upper and anterior angle of which is formed by 

 it. The principal frontal bones arc subtruncated anteriorly, and, in 

 consequence of the great development of the praefrontals, they do not 

 extend beyond the interobital space; they are scarcely longer than 

 the praefrontals, flat, and very shghtly concave betwee.i the jrbits. 

 The width of the interorbital space is less than the length of any of 

 the diameters of the orbit. The crow* of the head is flat, slightly 

 convex on the sides, and about twice as broad as long. The occi- 

 pital is quadrangular, rather broader than long. The suprascapula 

 appears to be composed of three pieces : the anterior joined to the 

 frontal and occipital, the middle and smallest one joined to the occi- 

 pital alone, and the posterior terminating in a long, flat, triangular 

 spine. These bones constitute the lateral portion of the crown of the 

 head. The basal portion of the brain-capsule is rather compressed. 



VOL. II. P 



