ANDREWS ON ORTilAGOltlSCUS OBLONGUS. 57 



nected with the palatine arch, which, by a suture, is united to the cra- 

 nium. The Orthagoriscus forms a section or sub-family of the Gymno- 

 dontes, by having no apparent teeth, the jaws being furnished inside 

 with an ivory-like substance, divided into laminae, and which, accord- 

 ing to M. Cuvier, are essentially true teeth united. The specific cha- 

 racters of this very rare and singular species are distinct from those of 

 0. mola, by the oblong form of body — the pectoral fins being pointed, 

 the skin being perfectly smooth and divided into irregularly-formed 

 hexagonal compartments, the sutures of which fit smoothly to each other, 

 the caudal fin being truncate or square, not rounded — this true caudal 

 fin being immediately connected with the dorsal and anal fins. Its 

 measurements are — 



From snout to extremity of caudal fin, . . . 23J inches. 



Breadth from mesial line on the back to abdo- 

 minal edge of the belly, 13^ ,, 



Length from snout to the eye, 3^ ,, 



Do. to anterior base of pectoral fin, ... 9 „ 



Do. of pectoral fin, 5 ,, 



The dorsal and anal fins are long and gradually tapering — 



Extreme breadth of dorsal at the base, ... 3 J inches. 



Length of do., 7| „ 



Anal fin, extreme breadth, ....... 3 ,, 



Do. in length, 6J „ 



Breadth of caudal fin, 8J ,, 



Depth of do., If „ 



The number of fin rays are — pectoral, 13; dorsal, 18; anal, 17; caudal, 

 19; probable weight, when captured, 16 lbs. 



The colour of the back was of a dusky amber brown, in the lighter 

 shades or variegations of which the hexagonal plates of the cuticle are 

 strikingly seen : the sides silvery white, marked from the mouth with 

 double lines of waved stripes pointing downwards, and which assumed 

 a maculated appearance, passing into fainter lines beneath the pectoral 

 fins ; abdomen dusky brown, becoming of a beautiful pink or flesh 

 colour around the anal and urinary vents ; aperture of the eyes nearly 

 round, 1-| inches in breadth ; iris silvery white, pupil dark and promi- 

 nent, protected by a nictitating membrane ; branchial orifice or spiracle 

 small, semilunar, placed immediately anterior to the base of attachment 

 of the first pectoral ray. 



Of its internal organization I regret that the opportunity was lost 

 of examination. Its state of decomposition was such, on being opened, 

 that it was not without much difficulty and care its skin was preserved 

 in a perfect state. The internal skin covering the body was formed of 

 a pale flesh-coloured tissue, the colour being uniform throughout, and 

 although extremely thin beneath the eyes, and anterior to the pectoral 

 fins, yet showing no trace of the waved lines that marked the external 

 cuticle, and which were confined to, and appeared the permanent mark- 



VOL. VI. I 



