20G THE PLAGIOSTOMIA. 



the anterior half of the total length; fin narrow, free portion as long as the base, 

 upper angle rounded, hinder not produced. Length of second dorsal equal 

 that of the first; height greater in second and hind angle produced; origin above 

 or little behind the middle of the bases of the ventrals. Base of ventrals equal to 

 its distance from the caudal, outer angle very blunt, rounded, posterior acumi- 

 nate, not extending as far back as the end of the second dorsal; axils below the 

 spine of the latter. Caudal short and deep, a well developed subcaudal lobe, 

 a notch in front of the terminal fin. Claspers of male extending little beyond 

 the end of the fin, ending in a slender point at the upper side of which is a long 

 sharp spine. Scales similar to those of C. coelolepis; those on the flanks and back 

 are comparatively smooth and there is a rounded depression above the pedicel; 

 on those over the head, shoulder and belly there are 3-5 weak keels. 



Dark brown, slightly mottled and clouded. 



Japan. 



Centroscymnus cryptacanthus. 



Centrophorus (Centroscymnus) coelolepis Gunth., 1870, Cat. fishes Brit, mus., 8, p. 423. 



Centroscymnus coelolepis Jordan & Gilbert, 1882, Bull. 16, U. S. nat. mus., 17; Jord. & Everm., 1890, 



Bull. 47, U. S. nat. mus., p. 55, (not fig). 

 Centroscymnus cryptacanthus Regan, 1906, Ann. mag. nat. hist., ser. 7, 18, p. 437. 



Length of snout from mouth greater than the distance between eye and first 

 gill opening. Length of anterior labial fold about equal to its distance from the 

 symphysis. Upper teeth small, narrow, lanceolate. Internarial distance less 

 than half the preoral length of the snout. Pectoral not extending to a vertical 

 from the first dorsal, hinder angle rounded. First dorsal shorter than second, 

 base about half the height, or one sixth of the interdorsal space. Base of second 

 dorsal, without the spine, three fourths of its distance from the caudal. Dorsal 

 spines short, hidden beneath the skin. Ventrals reaching a vertical from the 

 end of the second dorsal fin. Scales smooth with a depression at the base, except 

 those on the head and upper and lower parts of the body to the first dorsal each 

 of which has three parallel keels, produced behind the edge. 



Uniform dark brown. 



Type a male of about 27g inches, from Madeira. 



Centroselachus, gen. now 



Body elongate, head and tail short. Snout intermediate between that of 

 Acanthidium and that of Centrophorous, produced moderately, depressed, broad. 

 Nostrils oblique. Mouth transverse, with grooves and labial folds. Upper 



