IIOPLOSTKTIIUS PACIFICUS. 57 



Depth of head equal to its length, which is twice its width; forehead very 

 convex, a prominent median ridge above the nostrils. Snout short, hardly 

 as long as the eye, blunt, steep and strongly curved above the mouth, most 

 prominent forward in the angle at the mandibular symphysis. Nostrils 

 small, immediately in front of the eye; hinder larger, vertically oblong; 

 anterior small, round, lower than the posterior. Eye large, prominent, 

 one fourth as long as the head, less than the width of the intcrorlji- 

 tal space, considerably below the level of the top of the head. Skull 

 deeply excavated for the lateral system ; the channels of the system, 

 between the bridges protecting the disks, are covered by very thin and 

 dehcate membrane in whicli there are numerous minute pores. Mouth 

 large, oblique; lower jaw longer; maxillary visible backward of the nostrils, 

 broadening till nearly as wide as the eye at the end, curving downward in 

 the middle of the upper edge, not entering the mouth border, with a supple- 

 mental bone as long as the orbit. Teeth in villiform bands on jaws and 

 palatines, absent from the vomer. A prominent angle at the mandibular 

 symphysis, another below the articulary; a spine-like prominence behind the 

 scapulary, and another at the angle of the preopercle. All exposed por- 

 tions of the skull are roughened; the bridges crossing the canals of the lat- 

 eral system are comparatively strong, though the bony structure generally 

 is fragile. Edges of gill covers thin and membranous ; operculum twice as 

 high as long. Gills four; lamella3 of medium length; rakers six plus fifteen, 

 acicular, shorter than the eye. Pseudobranchite moderately developed. 

 Suprabranchial gland of medium size, vertically oblong or subelliptical, 

 with a groove in the middle, resembling that of Lamprogrammus but not 

 quite so annular. The position of this gland and the arrangement of the 

 disks of the lateral system on the head, with several of the anterior disks 

 of the body, are shown on Plate LXXL, fig. 4. Scales irregular, somewhat 

 convex, more or less rough with ridges or crowded small spines or granula- 

 tions, in about fifty-eight transverse series ; scales of the lateral line twenty- 

 eight, much larger, prominently convex, forming a strong ridge along the 

 side. The scales of this line belong to alternate ones of the transverse 

 series, but each scale in the line is so large as to crowd out the scales of the 

 intermediate rows, thus forming a continuous row of large scales. In the 

 median abdominal series there are about eighteen sharp scales, varying from 

 fifteen to nineteen. 



Dorsal orio-in midwav from anterior nostril to end of the base of the 



