1899.] NATURAL SCIENCES OF PHILADELPHIA. 493 



TEUTHIDID^. 



13. Monoceros vlamingii (Cuvier aud Valenciennes). 



jVaseux vlamingii Cuvier and Valenciennes, Hist. Nat. Poiss., X, 1835, 

 p. 216. 



Form of the body obloug ovoid, very much compressed. The 

 greatest depth of the body about the anterior part aud about 3 in 

 the total leugth without caudal filaments. Head, from tip of the 

 snout, 5| in total length (excluding filaments), its greatest depth 

 in that of the body not quite 2, much shorter than the length of 

 the head, and equal to the space between the tip of the rostrum 

 and the origin of the D. The rostrum or horn-like projection 

 does not extend beyond the tip of the snout and with its apex 

 bluntly rounded. The interorbital space very strongly convex 

 and contained nearly 2 in the snout and 3 in the head. Nostrils 

 in an oblique slit directly in front of the eye. Eye situated high 

 in the head, the lower half horizontal with the rostrum or horn 

 and posterior 4^ in the head, 1^ in interorbital space and 2f in 

 snout. Space between tip of snout and posterior margin of eye 

 and space between posterior extremity of maxillary and upper 

 posterior edge of operculum equal. Teeth small, even and smooth, 

 without groove, conical and without sharp edge. Prteoperculum 

 very oblique, forming an obtuse angle anterior to the eye. Origin 

 of the P. below the mouth, radii ii, 15, equal to the space between 

 the points formed by the branchial aperture. Origin of the D. 

 slightly behind the eye, anterior to the branchial aperture, on a 

 line with which the P. is inserted and with large strong spines, 

 the radii vi, 26, and of uniform length. Origin of V. behind 

 P., radii i, 2, the spines roughened and strong. Origin of the 

 A. below the last D. spine, radii ii, 27, its base equal to the soft 

 D. which it greatly resembles. Two large keeled immovable 

 laminae on the caudal peduncle, which is small, with the keels 

 projecting forward. Caudal triangular in shape, the upper and 

 lower outer rays produced into long filaments which project for a 

 space beyond the fin, equal to the depth of the body. Posterior 

 margin of caudal truncate. Body covered with very small granu- 

 lations which are rough to the touch, this roughness extending 

 over many of the spines of the fins and entirely over the caudal. 

 General color dark blackish brown, the upper part of the trunk 

 with indistinct blackish spots and the lateral and lower portions 



