Fishes. 



6453 



throw it out altogether. The growth of these animals is most extra- 

 ordinary ; in June, as I have before stated, they were about nine inches 

 long : in three months they attained their present size, which cannot 

 be less than eighteen inches in length. It rises frequently perpendi- 

 cularly to the surface to breathe, and at other times it supports itself 

 on its fin-like appendages, and, with the aid of its tail, raises its body 

 from the ground, the fins being bent or curved backwards. The move- 

 ment of this animal is generally very slow, and would give one the idea 

 that it was very sluggish ; this, however, I have good reason to know 

 is not the case, as in attempting to capture the one at liberty in the 

 large basin it darted away with the rapidity of an arrow. I have reason 

 also to believe the animal finds its food as much by scent as by sight. 

 With reference to the cocoon, the end covering the nose of the animal 

 is rather pointed, and has an aperture about the size of a pin's head, 

 which I have no doubt enables the animal to breathe through during 

 its state of torpor. The animal, when in its case, is coiled nearly 

 twice round, and I observed in each of the blocks of clay a small hole 

 about the size of a mouse-hole, which was quite smooth on the inside, 

 as though the animal had crept through it." 



Dr. Gray, to whom this admirable letter of Mr. Bartlett's is 

 addressed, publishes the following additional particulars, and ap- 

 parently from actual observation : — " The mouth is firmly closed by 

 the overhanging upper lip, except in front, where there is a small 

 oblong transverse horizontal opening 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 gene- 

 rally 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 



