230 THE VOYAGE OF H.M.S. CHALLENGER. 



gill lamiuaj short, especially on the convex portion of the arches ; gill-rakers long, 

 lanceolate, closely set, 20 + 10 on the outer branchial arch. 



The bones of the shoulder-girdle project at the symphysis as two rather long pointed 

 spikes. 



The vent is much nearer to the root of the caudal than to the gill-opening. The 

 dorsal fin commences immediately above it, the anal behind ; both fins are very similar 

 in shape and of moderate height. Caudal peduncle more than half as deep as long, its 

 depth being increased by a fold of the integument between the vertical fins. Caudal 

 fin rather short and forked. Pectoral fin very short, only half as long as the eye and 

 directed towards the back. 



Scales small, cycloid, each with a longitudinal keel which is not composed of spines 

 as in Macrurus, but simple as in the keeled scales of a snake ; the striations, instead of 

 continuously crossing the scale, are interrupted by the raised median line. Head entirel)^ 

 scaleless. Lateral line straight, running along the middle of the body and tail, and 

 composed of very small pores. 



Brown ; head, pectoral region, the vent and fringes of the caudal peduncle black. 



Xenodermichthys. 

 Xenodermichthys, Giinth., Aun. and. Mag. Nat. Hist., 1878, vol. il p. 250. 



Body rather elongate, compressed, without true scales. The skin is rather tough, 

 finely wrinkled longitudinally, with numerous small nodules, regularly arranged, which 

 possess the structure and probably the function of luminous organs. IMinute, rudimentary, 

 scale-like j^roductions are embedded in the skin, especially on the trunk. Mouth very 

 small, with feeble jaws and rudimentary teeth in the intermaxillary and mandible, and a 

 few in the maxillary. Palate toothless. Dorsal and anal fins equal in length. Caudal 

 forked. Gill-opening wide, but not extending much above the level of the pectoral fins. 

 Gills well-developed ; pseudobranehise. Gill-rakers long. 



Xenodermichthys nodulosiis (PI. LVIII. fig. C). 



Xenodermichthys nodulosus, Giintb., Aim. aud Jlag. Nat. Hist., 1878, vol. ii. p. 250. 

 D. 33. A. 33. P. G. V. 5. 



The height of the body is nearly one-seventh of the total length, without caudal ; the 

 length of the head two-elevenths. Eye of moderate size, its diameter being more tlian 

 the width of the interorbital space. Uniform black. 



Habitat. —South, of Yedo, Station 232; depth, 345 fathoms. One specimen, 8 

 inches long. 



