THE GAME FISHES OF THE FERSIAN GULF. 727 



€OuiCcil teeth on the gullet, both on the upper and lower surfaces, of the 

 same description as those on the jaws, and small villiform teeth on the 

 gill-fringes. Both jaws are provided with lips which are slotted on the 

 inside ; the conical teeth tit exactly into these slots ; the lips are 

 moveable. When the lips are not drawn outwards the large canine 

 teeth are barely visible. This feature is worthy of remark. 



Colour. — Head and back greenish, belly white, and sides iridescent. The 

 white of the sides varies with different specimens. In some it is clean, while 

 in other types it is distinctly dirty ; in fact the latter fish are darker in 

 shade all over. This difference in the degree of shade is probably due to 

 environment ; the light Pirao would obtain his brighter line from lying over 

 sand in shallow water whereas the more sombre-coloured individual would 

 hale from deep water. A similar phenomenon is quite, common in the 

 small burns of the Highlands. The lively yellow creature " bedropped with 

 crimson hail " is snatched from the shallows. His negro-tinted brother is 

 dragged from some deep hole or overhanging bank. It was frequently 

 surmised whether the dusky Pirao was a recent arrival from the open- sea, 

 where his drab colouring would harmonize with the twilight of his abysmal 

 surroundings. This conjecture is probably substantially correct. 



Eye. — Large, iris partly coloured golden, with distinct adipose lid situated 

 posteriorly. 



Lateral line. — Starts from the upper termination of the gill-opening, sweeps 

 in a low arch downwards to a point vertically above the base of the anal fin, 

 whence it continues straight to the fork of the tail. At the commencement 

 of the straight portion the lateral line is composed of hard scales in the form 

 of plates or shields which increase in size and substance as they approach 

 the caudal fin. At a distance from the fork of the tail equal to about half 

 the depth of the fish the shields develop into a most pronounced and well- 

 defined keel which terminates at the root of the caudal fin in a series of 

 jagged bony or horny cusps. Thus the free part of the tail instead of being 

 compressed vertically to correspond with the lobes of the caudal fin are 

 flattened horizontally. 



Scales. — The body is covered with small scales, but these are absent on 

 the central line of the head from the crown to the snout. 



Fins. — Anterior dorsal consists of four strong spines connected by a thin 

 transparent membrane. The most anterior spine originates as two separate 

 spines, but these unite towards their extremities into one composite spine. 

 The anterior dorsal iin fits into an exquisitely fashioned slot, so that when 

 the fin is closed the anterior spine lies flat Avith the back and exactly fills 

 up the top of the cavity. 



Posterior dorsal. — A firm connected fin without defined spines, curving 

 back to a length equal to about ^ the depth of the fish. 



ATial. — Length and appearance similar to the posterior dorsal, but situated 

 slightly nearer the tail ; both the posterior dorsal and the anal fins are 

 continued towards the tail by a connected fringe which terminates in a 

 slightly elongated piece of cuticle at the point where the lateral line 

 merges into the lateral keel. Situated anteriorly to the anal fin, and at a 

 distance from it equal to about J or | of the length of the posterior dorsal, 

 are two small sharp spines. 



Pectoral. — A long, narrow, delicate, falciform fin about equal to the deptn 

 of the fish. The fin-pit is marked by a black blotch. , , 



Caudal is forked and about equal in spread to the depth of the fish. 



Anus is situated closer to the pelvic than to the anal fin. 



Opercular spot absent. 



Remarks. — It will be noticed that Day states that Caranx jarra is provided 

 with villiform teeth on the tongue, whereas they would seem to be absent 

 14 



