202 THE PLAGIOSTOMIA. 



Nostrils in the anterior two fifths of the snout from the mouth, their distance 

 apart equals little more than their distance from the end of the snout; valve 

 with a sharp process in the middle. Eye large, length of orbit greater than that 

 of the snout in front of it. Mouth large moderately curved, with a deep groove 

 and labial folds at each angle; upper fold nearly half the length of the jaw. 

 Teeth compressed, triangular, sectorial; upper nearly erect in front, more 

 oblique at the sides; lower oblique, little wider than the upper, with fine serra- 

 tions on the edges. Width of gill openings less than length of orbit, upper ends 

 in front of the pectorals. Pectorals longer than wide, inner angle much pro- 

 duced, reaching behind the dorsal spine. Origin of first dorsal behind the axil 

 of the pectorals, fin entirely included in the forward half of the total length; 

 base, not including the spine, one third of the interdorsal space. Base of second 

 dorsal three fourths as long as that of the first, hind angle reaching a vertical 

 from the origin of the subcaudal. Dorsal spines strong, nearly half exposed, 

 anterior the shorter and not as high as the fin. Bases of ventrals wholly in 

 front of the base of the second dorsal, the short claspers reach below the spine 

 of that fin. Scales small, sessile, rising to a point with convergent keels or striae, 

 smoother with wear in age. Caudal less than one fourth of the total length, 

 rather deep, with a weak subcaudal lobe, terminal fin preceded by a shallow 

 indentation behind the subcaudal. 



Light brownish to greyish brown. 



Mediterranean and adjacent Atlantic. 



Centrophorus tessellations. 



Centrophorus tessellatus Garman, 1906, Bull. M. C. Z., 46, p. 205; Regan, 1908, Ann. mag. nat. hist., 

 ser. 8, 2, p. 54. 



Body subfusiform, robust. Head including the gill openings about one 

 fourth of the total, depressed, flattened below and on the crown, sides steep. 

 Snout long, broad and bluntly rounded at the end. Nostrils nearly transverse, 

 their distance apart equal their distance from the end of the snout, or less than 

 two thirds of that from the mouth; valve with an oblique angular lobe which 

 bears on its inner side a lobule. Eye large, less than half the length of the snout 

 from the mouth, hind extremity of orbit above the mouth. Width of mouth 

 three fifths of the length of the snout, little curved, a long deep straight groove 

 with labial folds extending one third the length of each jaw, at each angle. 

 Teeth compressed, serrated on the basal portions of each cusp, in ff rows; upper 

 erect in the middle of the mouth, becoming oblique toward the angles, each tooth 



