40 



largest. The pveopercnlutn is vertical, curved in the arc 

 of a circle, without any under limb. The interoperculum, 

 triangular and small, lies wholly behind the limb of the 

 preoperculum. The gill-cover is large. The operculum 

 is semi-orbicular, approaching to heart-shaped, and is 

 crossed by a furrow above its middle. The suboper- 

 culum is not quite two-thirds less, and forms, as usual, the 

 tip of the gill-plate. Its apex is marked by five minute 

 teeth, with furrows running backward from between them 

 for a short distance. The disk of the gill-plate is covered 

 by large scales, but some appear to have fallen from our 

 specimens. 



The head makes one-fourth of the total length of the 

 fish, and the height of the head measures about one-fifth 

 of the same distance. The thickness of the body is equal 

 to about two-thirds of its height anteriorly. The com- 

 pression augments posteriorly. The back is rounded off, 

 but the dorsal stands on a small ridge. There is a flat 

 space behind the adipose fin, which seems to have been 

 occupied by a soft glandular substance, like that on the 

 forehead. The belly is also obtuse, and a flattish space 

 exists before the ventrals. 



The pectoral fins reach to the anus, being larger than 

 those of any Mediterranean Mijctophum described by the 

 Prince of Musignano. The ventrals are placed midway 

 between the tip of the snout and end of the anal, and the 

 first dorsal commences immediately over them. The adi- 

 pose fin is fibrous, but does not possess the rudiments of 

 true rays. 



The scales composing the lateral line are oval, with a 

 short projection in the middle of one edge, and a simple 

 tube on the disk. The axis of the oval is vertical, and 

 the scales are conspicuous among the others ; there are 

 about thirty-five in all, the number between the anus and 

 caudal being exactly twenty-three. The other scales are 

 irregularly orbicular, and more or less oblique, according 

 to their position. Their free edges are entire, and their 

 bases show two or three slight lobes, with a coiTesponding 

 number of faint diverging furrows. 



The body is ornamented with many spots, each of which 

 is composed of a round opal-looking dot, set in a black 

 border, and they shine with much lustre through the 

 scales that cover them. A row, containing five of these 

 spots, crosses the najje from one supra-scapular to the 

 other. There is one solitary spot in the gill-plate, where 

 the operculum overlaps the suboperculum, and another one 

 on the interoperculum. On a level with this last there 

 follows one on the coracoid bone, another on the base 

 of the pectoral, and three more on the flanks behind that 

 fin, the row terminating over the anus. Two spots occur 

 on the scales of the lateral line, beneath the tubes, one of 

 Ihem over the anus, and the other over the middle of the 

 anal fin. Twelve exist on each side of the ventral surface of 

 the fish, beginning at the lower jaw, which has three on 

 each limb, and ending at the anus. There are seventeen 

 or eighteen in a row, which runs along the base of the 

 anal, and a short way beyond it. Also two close to the base 

 of the lower lobe of the caudal on each side. Lastly, there 

 is a single mesial one on the upper surface of the tail, 

 contiguous to the caudal. 



Four species are described in the Fauna Italtca, and 



with none of these is this species likely to be confounded. 

 Its pectorals exceed theirs considerably in size. The eye 

 is likewise much larger, and the dorsal more on the sum- 

 mit of the dorsal curve than in Myctophum punctatum, 

 while the forehead is much less high and precipitous than 

 the faces of the three others. 



Length, A^ inches. 



Hab. The sea between Australia and New Zealand. 



Myctophum coruscans. Richardson. 



Ch. spec. Myct. valde compressum ; longitudine capitis 

 altiliidineque. corporis <equalibus quartam partem longi- 

 tudiuis ad inilium pinncB caiid<B (Bqiiantibus ; ocnlo 

 modico super medium rictum oris grandiuscidum posito; 

 apparatii Iticido fronlali vix iillo vel ad regiones 

 nariiim restricio, ibique carina ossed mediand diviso. 



Radii: — D. 12; A. 20; C. 

 Plate XXVIL, figs 1- 



17|; P. 17; V. 8. 

 -5 inclusive. 



On a drawing of this species, by Dr. Hooker, there is a 

 note, stating that it was taken, at intervals, between St. 

 Helena and the Island of Ascension, in the evening, or 

 during the night ; and in the journal of the same observer, 

 I find a record of this, and Myctophntn boops, having been 

 taken on the 10th of August, 1841, between Australia and 

 New Zealand, in the night time, only when the Entomos- 

 traca and other marine Crustacea on which they feed 

 come most abundantly to the surface. 



The Mediterranean species to which this fish bears the 

 nearest resemblance, is the Myctophum puuctatum, both 

 in general form, and in the smallness of the shining frontal 

 apparatus. It is a much more compressed fish than the 

 preceding, particularly posteriorly, where it tapers much 

 into the very slender tail. The eye is a little removed 

 from the profile, and is placed rather before the middle of 

 the cleft of the mouth. The interorbital space is convex, 

 without any appearance of the glandular substance, which 

 seems to be confined to the immediate border of each 

 nostril. An elevated acute mesial line separates one nasal 

 prominence from the othei-. The preoperculum slopes 

 moderately backwards. The ventrals are attached at the 

 commencement of the second third oi' the length of the 

 fish, caudal excluded. The dorsal commences a little 

 behind them ; and the upper surface of the tail, behind the 

 adipose fin, is covered by six convex scales, without the 

 flat surface or glandular apparatus of the preceding spe- 

 cies. The posterior rays of the dorsal and anal are divided 

 to the base. There are no spines at the base of the 

 caudal, nor apparently any glandular substance on the 

 upper edge of the tail between the adipose and caudal 

 fins. The scales are undulated, and very irregularly and 

 sparingly toothed on the free edge, and have about three 

 basal furrows. Those which compose the lateral line, being 

 thirty-eight in number, are conspicuous, from their different 

 shape {vide figs. 3, 4, 5). 



The spots are distributed nearly as in Myctophum boops. 

 There are eighteen over the anal, exclusive of the two at 

 the base of the caudal. 



Only a single row of minute teeth can be seen on the 



