DISCUSSION OF SPKCIES AND THEIR DISTRIHUTION. 425 



of tlie pectoral that a vertical from the axil of tlie latter would touch the inner ventral ray 

 about at its middle (as shown in Vaillant's figure). In B. macroj)s the ventral is behind the 

 vertical froin base of pectoral ; its length is li times that of the snout (in i?. viacrops 3 thiwi^.) 



Radial formula: D. lx+102; A. !)7; V. S. 



Color, ruddy, silvery gray, with reflections; interior of mouth and branchial cavity black. 



Ninety-six specimens of this form were obtained by the French vessels, off the coast of 

 Morocco and Soudan and off the Canaries, in 834 to 1,590 meters. 



It is similar to B, macrops, which, however, has a small barbel, more rays in its vertical 

 fins, longer veutrais— set behind pectorals, instead of in advance of them— and anal set 

 further back. 



Family LYCONIDyE. 



Lyconidw, Gi^nther, Challenger Report, xxii, 1887, 158. 



Body terminating in a long compressed tapering tail, covered with small scales. A 

 continuous dorsal fin occupies the back to the extremity of the tail, but a division into two 

 portions may be considered to be indicated by the prolongation of some of the anterior dor- 

 sal rays; anal long, extending from the vent to the end of the tail; no caudal; ventrals 

 thoracic, composed of several rays. Pseudobranchia' present; 4 gills; 7 branchiostegals. 



Eelated to the Macrurida;, but to be considered as a more generalized type. {Criinther.) 



LYCONUS, Gunther. 

 Lyronus, GfiNTnER, Challenger Report, XXII, 1887, 158 (type, L.jnnntilHs, Inc. cit., pi. XLii, fig. C). 



Head and body compressed, the former composed of thin bones, but with narrow mucif- 

 erons channels, except on the top between the eyes; trunk as long as or longer than the 

 head; eye large; snout short; cleft of the mouth wide, terminal, both jaws armed with a 

 series of widely set teeth, unequal in size; two in front of the upper jaw being canine-like 

 but not so large as those of the lower jaw; vomer with a single canine-like tooth on each 

 side. Scales very small, cycloid, deciduous. Gill-membranes not united. Barbel none. 

 (Gilnther.) 



Til is unique tji^' of fishes is represented by a single specimen of the single species, 

 Lyconus pinnatus. 



LYCONUS PINNATUS, Gunthek. 

 LyronuH pinnotun, GuNTnEK, Challenger Report, xxii, 18S7, 158, pi. 42, fig. C. 



Head compressed, as deep as it is long, without snout. Tlie interorbital space is rather 

 flat, narrower than tlie round eye, which lies iuunediately below the upper profile: its 

 diameter is one-third of the length of the head and rather longer than the snout. The 

 mouth ascends obliquely forward, and extends behind the middle of the orbit; the jaws 

 are even in front. The teeth are but few in number, and besides the two long lateral fangs 

 there are only three shorter ones developed in the lower jaw. Opercular bones very thin, 

 and the infraorbitals narron, separating the maxilla from the eye by a narrow space oidy. 



The distance of the vent from the root of the ventrals is rather more than the length 

 of the head. The tail tapers into an exceedingly fine filament. 



The dorsal fin connnences above tlie base of tlie pectoral, and is composed of very 

 delicate simple rays; there is no break in its continuity, but some of its anterior rays, 

 perhaps 3 or 4, are much prolonged, but as this portion is injured, no more precise inforiii:i- 

 tion can be given. The anal fin commences immediately behind the vent, and its rays are 

 considiirably shorter than those of the dorsal. The pectoral has a narrow base, and is 

 directed obhquely upward ; it consists of thirteen rays, and is exceedingly elongate, the 

 middle rays extending far bevond the vent. 



The ventral fins are mutilat.-d; they are composed of 10 rays and situated beloiv- the 



base of the pectoral. 



Scales very small, thin, and deciduous. 



