92 ICHTHYOLOGICAL NOTES. 



Aspidontus, Quay &■ Gaimard. 



Aspidontus, Quoy & Gaimard, Voy. Astrolabe iii., 1834, p. 719 [A. teeniatus) ; Weber, Siboga 

 Exped. lvii., 191 3, pp. 539, 543. 



Macrurrhynchus, Ogilbv, P.L.S.N.S.W. xxi., 1896, p. 136 (M. maroubrai) ; Weber, Ibid., p. 539. 



Macrurrhynchus is here regarded as synonymous with Aspidontus, 'as was originally recognised 

 by Ogilby. Weber (Loo. cit.) considered them distinct on account of some differences in the form 

 and position of the gill-opening : in Aspidontus it is in front of, and as wide as the base of the pectoral ; 

 it is before the upper half of the pectoral-base in Macrurrhynchus , and is equal to about two-thirds its 

 width. The two genera appear similar in all other characters. 



Aspidontus appears to be distinguishable from Petroscirtes in having the gill-opening partly or entirely 

 before the pectoral base instead of above it ; the snout is conical and produced beyond the mouth ; 

 canine teeth present only in the lower jaw. 



Aspidontus maroubRvE, Ogilby. 



(Plate x. ; fig. 1). 



Macrurrhynchus maroubrce, Ogilbv, P.L.S.N.S.W., xxi. 2, 1896, p. 137. 



D. 12 ( + 2 ?), +31 ; A. 32 ; P. 12 ; V. 2 ; C. 11. Length of head, from end of snout to gill- 

 opening, 4.6 in the length from the snout to the base of the caudal rays ; depth of body 6.5 in the same. 

 Eye 3.4 in the head, slightly longer than the snout. Interorbital space wider than the eye, 3.1 in the 

 head. Gill-opening 1.8 in the eye, and 1.5 in the width of the pectoral base. Median pectoral ray 

 1.7 in the head, inner ventral ray 2.3 in the same. Second dorsal ray 2.1, twenty-fifth dorsal ray 2.3 

 in the head. Total length, from the snout to the end of the middle caudal rays, 50 mm. ; head 9} mm. 



Body elongate, compressed, deepest above the abdomen. Snout conical, deep, projecting beyond 

 the mouth, which is sub-inferior. Eye large, slightly longer than the snout, but not quite as wide as 

 the interorbital space ; the latter flattened. Posterior angle of the mouth extending almost to below 

 the middle of the eye ; anteriorly it forms a transverse opening, defined by the parallel upper and 

 lower jaws and by the mandibular canines ; the upper and lower jaws fail to meet in the type so that 

 there is always a wide aperture anteriorly. Teeth in a single series in each jaw, fixed, flattened ; the 

 upper are subvertical, and much larger than the lower, which are almost horizontal ; upper jaw without, 

 lower jaw with a large, tusk-like, curved canine on each side, which extends forward in advance of the 

 other mandibular teeth. Lips thin, not covering the teeth anteriorly, and forming a broad flap on each 

 side of the upper jaw. Nostrils close together, lateral, the posterior the larger, and in a low tube ; 

 they are placed midway between the eye and the end of the snout, almost on the angle between the upper 

 and lateral surfaces of the snout. Some minute pores regularly distributed over the head. Gill- 

 opening reduced to a small foramen before the upper angle of the pectoral-base. 



All the fins composed of simple rays. Dorsal fin originating almost above the preoperculum, and 

 slightly in advance of the ventrals. It appears to have been composed of forty -five rays, of which the 

 thirteenth and fourteenth are missing; the only trace of them remaining is a break in the continuity 

 of the fin, and two scars where their bases might have been. The second ray is a little longer than those 

 succeeding it, after which the rays increase slightly in length towards the middle of the fin, and then 

 gradually decrease backwards. Anal similar in form to, but lower than, the dorsal, commencing 

 beneath the fourteenth ray, and terminating evenly with that fin on the caudal peduncle ; last dorsal 

 and anal rays attached to the peduncle by membrane. Pectoral rounded. Ventral with two rays 

 enveloped in thick membrane, the inner the longer. Caudal emarginate. 



Colour, after preservation in alcohol, brownish above, lighter below, with numerous brown bars 

 on the upper half of the sides. Fins transparent, the dorsal and anal with several dark bars com- 

 posed of minute blackish dots, and with a narrow marginal band' of the same ; median caudal rays 

 similarly dotted. 



