196 Transactions 



The outer branchial is free only in its posterior half, the anterior portion 

 being adnate to the ceratohyal. This attached portion only bears gills ; 

 they are much smaller than those of the other arches, on which they are of 

 considerable length. There is no trace of paired arrangement in the gills 

 of this outer arch. A paired disposition is apparent in the gills of the 

 two middle arches, for, though the rays are set in continuous series, they 

 are of heteracanth nature. The inner arch is wholly adnate to the mem- 

 branes at the lower part of the tongue, and is fully furnished with gill- 

 rays. The gill-rakers are spiny tubercles ; there are 12 on the first arch, 

 one of which is on the upper limb, just above the angle ; the rakers on 

 the median arches are in two rows, arranged alternately, there being 19 

 on the second arch. 



Fins. — Some idea of the character of the dorsal tentacle will be derived 

 from Clarke's figures, but as it was evidently imperfect, and is even more 

 complicated than drawn and described, the following description will not 

 be out of place : — - 



The tentacle lies in a deep groove between the supraorbital ridges, its 

 bulbous base being rather nearer to the mouth than is the eye ; the shaft 

 is very stout, and it terminates above in a large semispherical bulb, its 

 total length from base to summit being 1-7 in the length of the head. 

 From a cup in the summit of the bulb arises a freely movable stout 

 tentacle, which divides at a short distance above its insertion, each branch 

 throwing off 2 smaller twigs at about half its height. Inserted in the 

 bulb and behind the cup are 2 thick b-anches, which, however, arise 

 from a common base : they become flattened distally, and each, after 

 throwing off a twig from its inner side, divides into 3 arms ; these are 

 again subdivided, but the divisions are not the same in the two branches 

 The illustration accurately depicts the condition. Also, on the hinder 

 part of the bulb, but nearer its base and sides, are two other small twigs. 

 The word " frond " would perhaps be more appropriate, for the whole 

 tentacle may be likened to a plant of Fucus, the so-named twigs being 

 quite like the fronds of a seaweed, while the main and secondary stalks 

 answer to the stem and branches of the plant. There are, in all, 

 20 terminal fronds, and the distal portion of each is nacreous white, 

 and is no doubt luminous in life. When the tentacle is bent forwards 

 these luminous tips dangle just in front of the mouth, and are no doubt 

 very effective lures. It will be apparent that the tentacle was incomplete 

 in the type specimen, the stalk arising from the middle of the cup being 

 absent, and doubtless leadinsr its author to conclude that the substance 

 within the cup was luminous, though he does not actually say so. 



The. dorsal fin has a slightly more forward insertion than the anal, and 

 has one more ray. The first is simple, the other four being divided nearly 

 to their bases. The third is the longest, being 3-2 in the head. The 

 last ray is connected to the peduncle, just free of the upper caudal ray. 

 The anal is very similar, but the first two of its 4 rays are simple. The 

 pectoral is short and rounded, and is placed nearly midway between the 

 end of the snout and the base of the caudal rays. The caudal is large 

 and rounded, arising from a very compressed and short peduncle, whose 

 depth is equal to the longest dorsal ray. 



Armour. — The skin is soft and loose, warty on snout and chin, and, 

 excepting the top of the head, cheeks, lower jaw, and all parts in front 

 thereof, studded with round cartilaginous scutes, each of which bears in 

 its centre a hard low thorn with roots radiating into the body of the scute. 



