194 TRIGLIDJ?;. 



margin ; it is placed horizontally, forming a great portion of the 

 upper surface of the snout ; its anterior margin is sharp, serrated ; 

 and tliore is a small spine, directed backwards, behind the centre 

 mentioned. The second bone is the smallest, triangular, with two 

 sides equal, and with the lower side shortest ; the centre is situated 

 in the middle of the lower side, and there is a spine behind it. The 

 third bone is the largest, irregularly quadi-angiilar, forming a long- 

 suture with the praeoperculum. The point from which the striae 

 radiate is excentric below the true centre, and armed with a very 

 small spine. A slight ridge, minutely serrated, runs from this point 

 to the angle of the prasoperculum. 



The pra3operculum and operculum form one continuous plane 

 with the bones cuirassing the cheek. The former has a ridge 

 across the angle, terminating in a strong spine ; there is a small 

 spine in the middle of the ridge, from which point the strioe 

 radiate, with which both limbs are provided. The opcrcidum is 

 strongly striated, and has two ridges, terminating in spines, the 

 lower of which is the stronger. The sub- and interoperculum are 

 narrow and smooth. 



AH the bones on the upper surface of the skull are rough with 

 tubercular striffi, radiating from the centre in each bone. The tm-- 

 binal bones are well developed, touching each other in front of the 

 ethmoid. The upper surface of the ethmoid* is quite free, sub- 

 rhomboidal, twice as long as broad, and not extending on to the 

 intcrorbital space. The prefrontals are large, fomiing a suture 

 together in the median line of the skull ; theii- orbital margin is 

 armed wdth an obtuse poiut. The principal fi'ontal bones do not 

 extend anteriorly beyond the intcrorbital space, which is concave, 

 and the ^vidtll of which is less than the length of the vertical dia- 

 meter of the orbit ; they are truncated posteriorly, separated from 

 the occipitals by an indistinct transverse groove ; there is a spine on 

 the posterior portion of the orbit, from which point the strise radiate. 

 The crowTi of the head is flat, broader than long, and the sutures 

 between the single bones have nearly entu-ely disappeared, except 

 the median one. The basal portion of the brain-capsule is slightly 

 roimded ; there is a foramen in the basisphenoid, immediately behind 

 the occipital joint. 



The suprascapula is firmly attached to the occipital, and terminates 

 in a long horizontal spine ; the scapula is oblong, broader inferiorly. 

 The coracoid is nearly straight, with two slender curved processes 

 for the junction wdth the scapula, and armed with a powerful spine 

 immediately behind these processes. Each pubic bone has two 

 limbs : the anterior is formed, as in other Acanthopterygii, by three 

 lamellse, the interior of which is the broadest ; the anterior hmbs of 

 both bones converge towards the symphysis of the coracoids, leaving 

 a wide free space between them, in which there is only a very short 

 process. The posterior limb is directed inwards, emitting a long 



* An examination of the development of tlie bones of tlie skull may show that 

 this is not the ethmoid itself, but a dermal plate coiTesponding to the ethmoid. 



