18 C1IONDEOPTERYUII. SELACIIOIDEI. 



pectoral with its upper edge nearly three times the width of the 

 lower. Second dorsal opposite anal, and nearly as large as the 

 first. Colour uniform. 

 Hab. Seas of India. 



2. Genus HEMIGALEUS, Bleeker. 

 Syn. Chccnoyaleus, Gill. 



Spiracles minute and behind the eye. Nictitating membrane 

 present. A pit before the root of the caudal fin both above and 

 below. Snout longitudinally produced. Moutli crescentic, with 

 labial folds. Teeth in the upper jaw denticulated, not so in the 

 lower. The first dorsal fin, which is destitute of a spine, is placed 

 opposite the interspace between the pectoral and ventral ; caudal 

 with a single notch. 



These fishes have been divided from Carcharias on account of 

 the existence of a rudimentary spiracle behind the eye, and like- 

 wise because the labial folds, which are rare in Carcharias, are 

 developed in all known species of the present genus. 



Geographical Distribution. Coromandel coast of India to the Malay 

 Archipelago. 



18. (1.) Hemigaleus balfonri. (Fig. 2.) 

 Hemigaleus balfouri, Day, Fish. India, p. 717, pi. cLxxxv, fig. 4. 



Fig. 2. Hcmiyalcus balfuuri, 



Length of the preoral portion of the snout slightly exceeding 

 the width of the mouth, and not quite equalling the distance 

 between the eye and the first gill-opening. Spiracle minute, situ- 

 ated about one half the diameter of the eye posterior to the orbit. 

 A groove at the angle of the mouth extending some distance along 

 each jaw. Nostrils situated nearer to the mouth than to the end 

 of the snout. The distance between the outer angles of the 

 nostrils equal to the width of the mouth. Gill-openings at least 

 twice the width of the orbit. Teeth g, those in the upper jaw 

 smooth, notched externally, or with about three denticulations 

 along the outer side of the base ; those in the lower jaw of a 

 slightly smaller size, erect and smooth. Finn pectoral falciform, 

 extending to below the first third of the base of the dorsal fin, the 



