156 BULLETIN OF THE 



M. sessilicauda. There are 30 rows of scales above and 32 below the lateral 

 line on the colored side. 



The lateral line of the colored side is strongly arched in its anterior part over 

 the base and anterior third of the pectoral fin. The arc of the curved portion 

 of the lateral line (10 ram.) equals 2^ times the height of the curve (4 mm.). 

 The curve is entirely similar to that of M. sessilicauda. The lateral line of the 

 blind side is nearly straight, very slightly ascending anteriorly. There are 105 

 scales in the lateral line to caudal base, 18 of these in the curved portion. 



The length of the head (24 mm.) equals | of the standard length and 2f 

 times the diameter of the eye. The distance from the snout to the front of 

 the upper eye (6 mm.) is much greater than the distance to the lower eye 

 (3 mm.). The inter-orbital area is a mere narrow ridge, whose width (1 mm.) 

 equals only ^ of the length of the eye. The length of the maxilla (8 mm.) 

 equals J the length of the head, and on account of its oblique position its hind 

 margin does not extend much beyond the vertical through the front margin 

 of the lower eye. 



The length of the mandible (10 mm.) equals ^ of the head's length. The 

 teeth are uniserial, and well developed on both sides. The nostrils are in very 

 short tubes, in the same line with the interorbital ridge, the posterior one being 

 slightly less distant from the lower eye than the anterior is from the tip of the 

 snout. A concavity above the snout. 



The dorsal fin begins upon the snout on the blind side in the perpendicular 

 through the front of the lower eye. It contains 124 simple rays, the longest 

 rays being in the posterior fourth of the fin, and half as long as the head. The 

 anal fin begins between the tips of the ventrals and under the origin of the 

 pectoral. The vent is not on the ventral outline, but on the blind side and 

 close to the beginning of the anal fin. The anal is composed of 100 simple 

 rays, the longest (14 mm.) being behind the middle of the fin and slightly 

 longer than the longest of the dorsal (13 mm.). The caudal is sessile, rounded, 

 the middle rays (20 mm.) about ^ of standard length of body.- The pectoral 

 is present only on the colored side, is inserted close to the edge of the oper- 

 culum, its length (27 mm.) exceeding that of the head, and contained 4^ times 

 in the standard length. The ventral of the colored side is nearly on the ridge 

 of the abdomen, while that on the blind side is mostly lateral and slightly 

 larger than its fellow. The length of the left ventral (7 mm.) is contained 

 about 3^ times in length of head. 



The color on the left side is light brownish gi-ay ; the fins are mostly dusky, 

 except the right ventral, which is pale ; the pectoral and the eyelids are 

 black. 



D. 124 ; A. 100 ; V. 6 ; P. 12. Scales, 30-105-32 (18 in curved portion of 

 lateral line). 



A single specimen (xvi.) was taken by the "Blake" off Barbadoes, in 288 

 fathoms, and another one (xvii.) in the same locality, at a depth of 218 

 fathoms. 



