206 TRIGLWM. 



I: Adult: stiiflfed. 



I. IIalf-gTo^^^l : skin. 



m. Half-grown : skin. From Gronow's Collection. 



9i-p. Adult : skeletons : not good state. English coast. 



Skeleton*. — The bones of the upper jaw can bo nearly entirely- 

 hidden below the prominent edge of the prajorbital ; the maxillary 

 reaches as far backwards as the mandibulary, and becomes gradually 

 broader posteriorly. The interraaxillai-y is shorter, has a flat promi- 

 nence behind, and the posterior processes very short. The mandi- 

 bula is rather low, and has some irregular longitudinal grooves, and 

 a few pores inferiorly. The vomer is very broad, with the anterior 

 edge swollen and with a longitudinal groove along the median line. 

 The teeth form a band, which is narrowest in the middle. The 

 palatine bones are subeEiptical, -with the posterior portion produced 

 and bent downwards. There is a single, exceedingly large bone, 

 cuii'assing the chock ; it extends from the extremity of the snout to 

 the interior edge of the prajoperculum, and from the mandibulary 

 joint to the anterior angle of the orbit ; the anterior portion of its 

 lower edge is swoUcn, porous, and obtusely crenatcd ; the point from 

 which the striae of the bone radiate, is situated a little above the 

 middle of the lower margin ; a series of pores corresponds to every 

 stria, and there is a granule of enamel in many of the pores. The 

 lower margin of the orbit appears to be formed by a single, narrow, 

 elongate suborbital, whilst there are two in other species of Trkjla 

 and Prlonotus. The prfcoperculum and operculum form one con- 

 tinuous plane with the prajorbital ; the former has a slight i-idge 

 (scarcely \'isible) across the angle, which is provided with two ob- 

 tuse points ; it is obliquely situated, and its lower limb is reduced 

 almost to nothing. The operculum has no distinct ridge, but two 

 spines, separated from each other by a deep notch ; there is another 

 semicircular notch above the upper spine. The sub- and interoper- 

 culum are narrow and smooth. 



The ethmoidal bone is large, sexangular, 1| as long as broad, and 

 separates the turbinal and prtefrontal from their fellows. The tur- 

 binal bones are large, triangular. The prefrontals are well de- 

 veloped, rather elongate, overreaching the anterior portion of the 

 orbit, and armed with a stout point. The principal frontal bones 

 are subtnmcated anteriorly, and do not extend beyond the inter- 

 orbital space, which is very slightly concave, and the width of which 

 is much more than the length of the horizontal diameter of the 

 orbit. The crown of the skirLl is quite flat, t\vice as broad as 

 long ; the sutures have entirely disappeared. There is no occipital 

 crest at all. The basal portion of the brain-capsule is neither com- 

 pressed nor swollen ; the basisphenoid is rather narrow, flat. 



The suprascapida is finnly joined to the occipital, forming a por- 

 tion of the upper sm-face of the skull, and terminates posteriorly 

 in a flat spine. The scapula is oblong, broader inferiorly. The 



* The description of the bones of the head is taken from a skull in my own 

 collection, eight inches long ; the fish was taken off the Brighton coast. 



