112 THE PLAGIOSTOMIA. 



SCOLIODON WALBEEHMI. 



Carcharias (Scoliodon) walbeehnii Bleeker, 1856, Nat. tijda. Ned. Ind., 10, p. 353; Dum6ril, 1865, 

 Elasm., p. 344; Gunth., 1870, Cat. fishes Brit, mus., 8, p. 359. 



Head elongate, pointed; snout one and one half times the length of the 

 mouth, rounded at the end. Mouth narrowing forward, rounded in front; 

 labial folds short, extended more on the lower jaws than on the upper. Nostrils 

 about twice as far from the end of the snout as from the mouth, distance apart 

 less than the length of the mouth. Eye small, orbit about half the length of the 

 mouth, less than the distance from the nostril, equal the width of a gill opening. 

 Hindmost two of the gill openings above the pectoral. Teeth in §1 rows, bases 

 broad, cusps obliquely inclined toward the angles of the mouth above a decided 

 notch in the hinder edge; median tooth in the upper series and the two syin- 

 physeal teeth in the lower smaller, nearly erect; inner or cutting edge concave 

 near the apex of the cusp. Scales minute, 5-carinate. Ventrals, second dorsal, 

 and anal small. Pectorals more pointed on the outer angle, more indented on 

 the hind margin, and sharper on the inner angle than on S. laticaudus. Origin 

 of first dorsal opposite the end of the inner angle of the pectoral, produced hinder 

 angle reaching a vertical from the origins of the ventrals. Length of anal base 

 less than half the distance from the bases of the ventrals, two thirds of its dis- 

 tance from the caudal. Base of second dorsal half as long as that of the anal, 

 end of fin not reaching the caudal pit. Caudal moderate, deep across the sub- 

 caudal lobe, slender backward. 



Back brown; lower surface white; fins dark with light margins, excepting 

 the upper edge of the caudal and the lower edge of the hinder portion of the 

 subcaudal which are dark. 



Total length 18, snout to pores 8|, snout to fifth gill opening 3|, and snout 

 to mouth Ij inches. 



Specimens described from Singapore and Columbo; Penang. 



Scoliodon porosus. 



Squalus porosus Poey, 1860, Memorias Cuba, 2, p. 339, tab. 19, f. 11, 12. 



Scoliodon porosus Poey, 1868, Repertorio, 2, p. 452; 1876, An. Soc. Esp. hist, nat., 5, p. 200. 



This species somewhat resembles S. terrae novae in shapes and proportions 

 and in positions of the fins. In comparing a Cuban specimen of S. porosus, from 

 Professor Poey, of about fifteen inches with one of S. terrae novae of equal size, 

 from South Carolina, the following divergences are patent : — S. porosus is the 



