Dr. J. E. Gray on Lepidosiren. 413 



recting its motions, and they evidently form part of the anterior mem- 

 bers. They are placed rather close together somewhat above the 

 base of the elongated finned filament. These limbs are used to sup- 

 port the animal some height above the surface of the gravel when it 

 is at rest. 



Indeed, all the motions of the animal much more resemble those 

 of a Triton or Lissotriton than of an eel-shaped fish. 



The upper and lower surfaces of the head are furnished with lines 

 of mucous pores placed in a symmetrical manner on the two sides, 

 similar to the pores observable on the head and chin of different 

 kinds of fish, and of Tritons and Lissotritons : and there is a distinct 

 continuous line of pores, like the lateral line of fish and Tritons, 

 which is continued on the tail some distance behind the base of the 

 hinder members, but becoming less distinct at the hinder part of 

 the series. 



The eyes are of moderate size, scarcely raised above the surface, 

 round, without any eyelids ; the pupil is black, small, circular, less 

 than one-third the diameter of the globe, with a narrow golden iris. 



The Mud Fish is generally to be observed swimming about under 

 the water, or resting at the bottom of the tank, supporting itself by 

 its members, an inch and a half or two inches above the surface 

 of the gravel, with its nose generally in the corner, bent down and 

 partly hidden in the gravel. 



The mouth is firmly closed by the overhanging upper lip, except 

 in front, where there is a small oblong, transverse, horizontal open- 

 ing on the outer edge of the lips, admitting the water to the small 

 open external nostrils, which are on the middle of the under side of 

 the upper lip. This opening does not extend to the hinder part of 

 the lips, which are closed behind it, so that water cannot enter the 

 mouth in that direction except through the nostrils. 



In this quiescent state the lateral gill-opening is generally closed, 

 but sometimes it is slightly elevated, and a small current appears to 

 be emitted now and then from it, as if a small quantity of water were 

 taken in by the nostrils and emitted by the gill-flap ; but this action 

 is not continuous nor very distinctly visible. 



While remaining under the water the animal sometimes opens the 

 mouth to its full extent, leaving it open for some time, dilating the 

 throat by the action of the os hyoides ; when fully dilated it closes 

 its mouth, opens the gill-aperture, and contracting the throat emits 

 a strong current of water through the lateral gill-aperture. 



It occasionally but at uncertain periods rises perpendicularly to the 

 top of the water, until the front part of the head and the whole 

 mouth are exposed above the water ; it then opens its mouth, which 

 it retains open for a time, dilates its throat, as if taking in all the air 

 it can contain, closes the mouth, descends under the surface and con- 

 tracts its throat, as if it were forcing the air into the lungs (sometimes 

 during this action one or two very small bubbles of air are emitted at 

 the gill-aperture), and then the animal takes up its old position near 

 the bottom of the vase. 



I once saw the animal ascend and so take in air almost imme- 



