DISCUSSION OP SPECIES AND THEIR DISTRIBUTION. C7 



[PNOPS Mi BRAYI, GOnther. (Figures 67, 68.) 



Ipnops Murniiii, 61 niiiii:, Ann. and Mag. Nat. Hist., 1878, n, 187; Challenger Report, xxii, L91,pl. \n\, 

 fig. IS. 



Body elongate, cylindrical; tail compressed behind; head depressed. The deptb of the 

 trunk diminishes l>nt little backwards, and is contained L3J times in the total length, with- 

 out caudal; the length of the head is one-sixth of the total. Head broad, much broader 

 than deep, its greatest depth being two-thirds of its length. Snout broad, much depressed, 

 with obtusely rounded anterior profile; cleft of the mouth verj wide, the maxillary moder- 

 ately dilated behind and extending beyond the middle of the length of the head. Man- 

 dible projecting beyond the upper jaw, broad, but owing to the depressed form of the snout 

 its upper surface is nearly entirely at the lower side of the snout. Infraorbital chain of 

 bones very narrow, wedged in between the transparent lamina and the maxillary, with four 

 \er\ distinct apertures leading into the mucous duet. The upper surface of the head, includ- 

 ing the snout, is wholly covered by the two cornea like laminae of the luminous apparatus. 

 They an' closely attached to each other along the median line, each being divided by a 

 shallow transverse ridge into a larger anterior and a smaller posterior portion. The ridge 

 turns forward near and parallel to the median line, and marks the course of a superficial 

 mucous duet. 



The gill laminae are well developed and the gill rakers long, needle-shaped, closely set, 

 about 22 in number on the outer branchial arch. 



The vent is nearly twice as distant from the root of the caudal fin as from the end of 

 the snout, and rather more than the length of the head from the gill opening; it is placed 

 between the ventral fins. 



The dorsal fin commences immediately behind the vertical from the vent; it is short, 

 but its longest rays are twice as high as the body. Origin of the anal midway between the 

 vent and the root of the caudal, composed of rays which are more slender and shorter than 

 those of the dorsal. Caudal fin narrow, subtruncated, more than half as long as the head. 

 Pectorals rather feeble, lateral, as long as the caudal, and extending to the ventrals. Veu- 

 trals are composed of stronger rays, horizontally placed and somewhat distant from each 

 other, as is frequently found in fishes habitually moving on the bottom ; they slightly exceed 

 the pectorals in length. 



The scales are large, thin, deciduous, forming only six longitudinal series on each side 

 of the trunk. Lateral line faintly indicated along the middle of the body; the muciferous 

 channels on the head are also narrow, with small apertures. Brown, fins colorless. Buccal 

 and branchial cavities and lower side of head black. (jQUnther.) 



Eadial formula: D. 10; A.13; P. 14; V.8; L.lat.55. 



The Challenger obtained it from the coast of Brazil, station 124; depth, 1,G00 fathoms 

 (one .specimen, 4.J inches long). Xear Tristan da Cunha, station 133; depth, 1,900 fathoms 

 (two specimens, 5£ inches long); and north of Celebes, station 198; depth, 2,150 fathoms 

 (one specimen, 4 inches long). 



It was also obtained by the Blake, station rrxxxin, lat. 24° 36' X., Ion. 84° 0.V \Y., 955 

 fathoms (one specimen), and station lxvi, off Bequia, 1,507 fathoms (one specimen). 



Family RONDELETIID^E, Goode and Bean. 



Body more or less compressed, scaleless. Head naked. Xo barbels. Mouth large. 

 Margin of the upper jaw formed by the prernaxillaries only. Teeth coarsely granular. 

 Opercular apparatus complete; its bones very thin, membrane like. Xo adipose tin. Dor- 

 sal tin far back; short and low; inserted opposite the anal. Pectorals short, placed rather 

 low. Ventrals present, abdominal, (lill opening very wide; membranes deeply cleft, free 

 from the isthmus. l'seudobranchi;e absent. 



