4 Messrs. Hancock and Embleton on a Gymnetrus 



in the neighbourhood of the head by irregular depressed indu- 

 rations of the skin. 



The head is small and short, measuring 9 in. from the snout 

 to the posterior margin of the gill- cover ; the outline of the lower 

 jaw is a wide arch convex below, and stretching forwards and 

 upwards to the mouth, which is placed in an elevated position 

 and opens upwards and forwards ; the mouth is small, nearly cir- 

 cular, and capable of being projected 2 or 3 in. forwards when 

 the low T er jaw is depressed. The profile of the head from the 

 anterior end of the crest is at first suddenly concave, the conca- 

 vity facing forwards and upwards, and just behind the anterior 

 end of the curve exists the nasal chamber which is small, and 

 owing to the damaged state of the fish we could only find one 

 small aperture, which was longer than it was broad. Beyond this 

 concavity the premaxillary bones project nearly horizontally to 

 the mouth. The eye is 1^ in. in diameter, the iris of a beautiful 

 silvery white, and rather broader than the diameter of the pupil. 

 The eye is situated 2 g- in. below the base of the crest and 1^ in. 

 behind the frontal concave profile. There is a narrow imperfect 

 circle of a dusky colour round the contour of the eyeball. The 

 eye is very flat. The tongue is rather prominent, but small, 

 smooth and fixed. There are no teeth. The interior of the mouth 

 is black. 



The gill-covers are large in proportion to the size of the head, 

 prolonged backwards, their posterior angles considerably ele- 

 vated. The preoperculum has somewhat of a crescentic form, 

 the lower border convex ; the anterior horn is narrow and pro- 

 longed to its articulation with the lower maxilla, the posterior 

 border has an obtuse angle pointing backwards. This border 

 corresponds to and may rest upon the edge of the concavity 

 formed by the operculum above and the interoperculum below. 

 The operculum is on the whole broad and irregularly quadrate, 

 with the upper anterior angle prolonged forwards and upwards ; 

 the upper margin is smooth and slightly concave nearly as far as 

 the angle, it then curves suddenly downwards a little to the 

 angle which is rather obtuse. Below this is the posterior border, 

 which is somewhat sinuous and rather oblique from above down- 

 wards and forwards. 



The inferior border is nearly straight, and directed upwards 

 and forwards corresponding to the interoperculum. 



The remaining bone, which we take for the interoperculum, is 

 narrow and thin, prolonged almost to a point under the jaw and 

 widening gradually to its posterior end, which is rounded and 

 projects backwards beyond the preoperculum. Its lower border 

 is convex and lies almost horizontally. 



These are the only pieces observed as entering into the forma- 



