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



,^ ' Family Lyconidje. 



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 

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

 thoracic, composed of several rays. Pseudobranchise present ; four gills ; seven 

 branchiostegals. 



I am obliged to propose a distinct family for the new genus described below, 

 as it differs in certain characters from the Macruridaj, by which this latter family has 

 hitherto seemed to be well defined. It may be considered to be a more generalised type 

 than the Macruridse. 



Lyconus, n. gen. 



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

 ferous 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. 



Lyconus pinnatus, n. sp. (PI. XLII. fig. C). 



Head compressed, as deep as it is long, without snout. The iuterorbital space is 

 rather flat, narrower than the round eye, which lies immediately 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 forwards, 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 narrow, separating the maxilla from the eye by a narrow space only. 



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 commences above the base of the pectoral, and is composed of very 

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

 perhaps three or four, are much prolonged, but as this portion is injured, no more precise 

 information can be given. The anal fin commences immediately behind the vent, and 

 Its rays are considerably shorter than those of the dorsal. The pectoral has a narrow base, 

 and is obliquely directed upwards; it consists of thirteen rays, and is exceedingly elongate, 

 tlie middle rays extending far beyond the vent. 



