8. I'TKROIS. 123 



I, m. Half-grown. Purchased of Mr. Frank. 



H, 0. Half-grown : very bad state. Cape Upstart; Presented by 



J. B. Jiikes, Esq. 

 p. Half-grown: very bad state. Sydney. From the Haslar Collection. 

 (/. Adult : stuffed. Australia. 

 r, s. Adult and half-grown. Old Collection. 

 t. Adult. 



Skeleton. — The structure of the skeleton does not differ in any 

 essential point from that of Seorpcena, or, in fact, from that of the 

 typical Percoid forms. The extraordinary development of the rays 

 of the fins is not accompanied by a similar development of the bones 

 to which they are attached, simply because these fins appear to have 

 no peculiar function, as in flying fishes, or in fishes where the spines 

 of the fins are effectual weapons ; they are, in Pierois, merely orna- 

 mental. 



The maxillary bone is styliform in its upper half, spatuliform in 

 its lower ; the intermaxillary has a very broad prominence on its 

 descending brancli, which is longer than the posterior process. 

 There is a free cleft between the dentaiy and articular parts of the 

 mandibula ; its muciferous channel is rudimentary. The anterior 

 margin of the head of the vomer is prominent, and armed ^vith a 

 band of villiform teeth. The palatine bones are rather broad, hori- 

 zontally sitiiated. The tiu'binal bone is thin, tubiform, armed pos- 

 teriorly with a feeble spine. The prasorbital and the infraorbitals 

 are tliin and rather broad ; the former has a rough surface, pro- 

 duced by ridges and grooves radiating from a centre,- — the latter 

 have a feeble, toothed, longitudinal ridge. The prajoperculum is a 

 crescent-shaped bone, with a distinct muciferous channel ; its margin 

 is armed with four spines, of which two, ojiposite to the infraorbital, 

 are the most prominent ; the two others, one at the angle and one 

 at the lower margin, are rather obtuse. The other opercular jjieces 

 are thin, flexible ; the operculum has a feeble ridge on its inner 

 surface. The anterior frontals are rather narrow, produced back- 

 wards, and terminate posteriorly in a very feeble spine. The 

 principal frontals diverge anteriorly to receive the ethmoid ; their 

 orbital margin is provided posteriorly -nith a spine, and elevated, thus 

 rendering the space between the orbits concave ; there is, moreover, 

 a longitudinal groove along the middle of the intraorbital space. 

 The crown is rather narrow, oblong, flat, ■with a ridge on each side, 

 which terminates posteriorly in a spine. The scapula is spiniferous, 

 the coracoid not. The basal portion of the brain-capsule is neither 

 compressed nor swollen ; the basisphenoid without groove or ridge. 

 The glossohyal small and styliform ; the lu'ohyal triangular, with 

 the posterior side notched. Each pubic bone is formed by thi'ee 

 lamellae, the intei'ior of which is the most developed and closely 

 adherent to its fellow. 



There are ten abdominal and fourteen caudal vertehne, the length 

 of the former portion of the vertebral column being to that of the 

 latter as 1 : 1-7. The centre of the second vertebra only is slightly 



