204 THE PLAGIOSTOMIA. 



oblique triangular cusps. Spiracles moderate, with a large prespiracular 

 cavity extending forward to the orbit. Dorsals small, spines hardly visible, or 

 hidden. No anal fin. Caudal rather short and deep, with a subcaudal lobe. 

 Pectorals small, inner angle not produced. Scales of the body pedicellate, 

 with crown depressed and smooth above the pedicel, edges striate to carinate; 

 scales of the head sessile, carinate. 



Snout from the mouth shorter than the distance from eye to first gill opening 

 first dorsal little the smaller; end of spines exposed 



scales of head striate ..... coelolepis (page 204) 

 Snout from mouth longer than the distance from eye to first gill opening 

 first dorsal much the smaller; end of spines exposed 



scales of head with 3-5 keels or striae . . owstonii (page 205) 



first dorsal the shorter; spines hidden 



scales of head with three parallel keels . cryptacanthus (page 206) 



Centroscymnus coelolepis. 



Plate 14, fig. 5-8. 



Centroscymnus coelolepis Bocage & Capello, 1864, Diag. fam. Squal., p. 3; Proc. Zool. soc. London, 

 p. 263, f. 4; 1866, Plagios., p. 30, pi. 2, f. 3; Wright, 1868, Ann. mag. nat. hist., ser. 4, 2, p. 426; 

 Vaillant, 1888, Travailleur et Talisman, Poissons, p. 63, pi. 2, f. 1; Goode & Bean, 1896, Mem. 

 M. C. Z., 22, p. 14, pi. 4, f. 13; Regan, 1908, Ann. mag. nat. hist., ser. 8, 2, p. 49; Jokd. & 

 Everm., 1900, Bull. 47, U. S. nat. mus., pi. 8, f. 25 (non description). 



Body robust, subfusiform, body cavity little more than two thirds of the 

 total length. Snout short, depressed, broadly rounded at the end. Nostrils 

 obhque, nearer to the end of the snout than to the mouth. Mouth wide, width 

 greater than length of snout, with a deep groove and with labial folds at each 

 angle ; lower fold not half as long as the j aw. Teeth in |§ rows ; upper lanceolate, 

 four or five series in function; lower broad, compressed, with cutting edge directed 

 obliquely toward the angles of the mouth, one series in function, except when 

 about to be dropped. The teeth on the upper jaws are much more numerous 

 than those of the lower, and are in three groups, that is a lower front group of 24 

 to 26 rows nearer the symphysis resting in front (outside) of the lower jaws and 

 occupying a more prominent position, and a lateral group near each corner of 

 the mouth of smaller teeth and resting inside of (between) the lower jaws. 

 Eyes large, orbit elongate, more than half the length of the snout, with a slight 

 angle in front and an angular fold in the skin behind. Spiracles half as long as 

 the orbit, opening upward. Gill openings narrow, not as wide as the orbit, 

 equally spaced, in front of the pectoral. Pectorals medium, not reaching a 



