210 THE PLAGIOSTOMIA. 



SCYMNODON PLUNKETI. 

 Cenlrophorus plunketi Waite, 1910, Trans. N. Z. inst., 42, p. 384, pi. 37. 



Head broad, depressed. Snout short, blunt; nostrils near the end, nearer 

 to the tip than to the eye, oblique. Mouth nearer to the end of the snout than 

 to the first gill opening, width half the length of the head, a deep groove and labial 

 folds at each angle, lower fold shorter. Upper teeth small, lanceolate, two- 

 rooted; lower, of 30 teeth, with cusp directed obliquely toward the angle. 

 Spiracle large, a little nearer to the eye than to the gill opening. Gill openings 

 half the diameter of the eye, in front of the pectorals. Dorsal spines not half 

 the height of the fins, with short exposure; first midway from the front of the 

 eye to the base of the second dorsal, length of base without the spine slightly 

 more than one fifth of the interdorsal space. Second dorsal much larger, base 

 and spine equal distance from base to caudal, spine above the bases of the 

 ventrals. Pectoral large, length equal to distance from tip of snout to first 

 gill opening, inner angle rounded, fin not reaching below the first dorsal. One 

 third of the bases of the ventrals lies behind the spine of the second dorsal. 

 Scales small, tricarinate, tricuspid, median keel and cusp longer. 



Uniform dark brown. 



Known from the description of the type, a female of near 4 ft. 8 inches 

 (1,414 mm.) taken off Riley's Islands, New Zealand in a depth of 120 fathoms. 



SCYMNODON MACBACANTHTJS. 

 Centroscymnus macracanthus Regan, 1906, Ann. mag. nat. hist., ser. 7, 18, p. 436. 



Snout from mouth equal to distance from eye to first gill opening. Nostrils 

 very oblique. Anterior labial fold about equal to its distance from the symphysis. 

 First dorsal shorter than second, base without spine equal two thirds of the 

 height and two ninths of the interdorsal space. Base of second dorsal, without 

 spine, equal two thirds of its distance from the caudal. Dorsal spines well 

 developed and strongly projecting. Pectoral reaching a vertical from the spine 

 of the first dorsal, inner angle rounded. Ventrals not reaching a vertical from 

 the end of the second dorsal. Scales with three parallel keels, each ending in a 

 point, median keel strongest. 



Type a female of about twenty-five inches. 



Magellan. 



