Fishes. 6813 



as those I got were uncommonly fat, and were so active and incessantly diving, I con- 

 cluded they had only newly arrived, as I am of opinion they cannot get their proper 

 food, as, after being a short time here, I have remarked that they soon get very lean 

 and eventually pine away. On the 5th instant I was fortunate enough to get four 

 more, but have uot seen any since. — Id. 



Occurrence of the Glaucous Gull in Orkneij. — 1 have seen four glaucous gulls 

 {Larus (jlaucus), in the first year's plumage, this winter, two of which I fortunately 

 obtained last week. — Id. 



On some Structural Peculiarities in the Pipe Fishes. — The specimen of the Syng- 

 nathus before us is dried so as to preserve and show a very beautiful apparatus which 

 exists under the lower jaw, and which I have not seen exhibited in any "of the museum 

 specimens that have come under my observation, nor have I seen it described. The 

 apparatus to which I allude is what may be called a " Derrick mechanism " fur en- 

 larging the opening of the mouth, and widening ihe throat in the act of swallowing. 

 As the Syngnathus is usually drawn or preserved in museums, the under line of 

 the jaw is nearly horizontal, the under line of profile deviating little from the hori- 

 zontal and showing no projection ; and looked at in a vivarium the aspect of the fish 

 is the same, and the only motion usually perceptible about the jaw is that of the sin- 

 ^ gular-looking fleshy lip, which projects upwards from the extremity of the lower jaw, 

 t with its valve-like action opening slightly to admit water for respiration, and then 

 I closing to aid the action of ihe tubular jaw in driving the water backwards through 

 the gills ; but this limited motion would not suffice for taking in food, and hence, 

 when the Syngnathus is about to swallow, the action of the mechanism I shall now 

 describe is brought into play. If the dried specimen be viewed laterally a process 

 about a quarter of an inch long is seen projecting downwards at right angles to the 

 jaw. If instead of the lateral view this process be looked at in front, it is seen to con- 

 sist of two limbs, or processes, like those of a derrick, one springing from the lower 

 jaw on each side and uniting at an angle in the centre. From this point of junction, 

 which appears to be ligamentary, an elastic tissue extends along the mesial line 

 between the two sides of the lower jaw to the valve-like lip, while behind a muscular 

 tissue exists, stretching backwards from the point between the operculum to what I 

 believe is the os hyoides. When the animal is alive the action of this mechanism is 

 very beautiful. In the mere process of breathing this apparatus does not come into 

 view at all. It lies quite hidden within the triangular space within the lower jaw, 

 and fits it, and fills the space so accurately that it is very difficult to detect it, and 

 even in the dead specimen the action of this elastic tissue keeps it so accurately fitted 

 in its berth that it may escape a very close examination. To return, however, to the 

 living animal, — when the Syngnathus is about to swallow it draws out by muscular 

 action the point of this derrick, as we may call it, from its receptacle. In so doing, 

 the point of it draws with it the ligamentary tissue extending to the lower lip until 

 the point is drawn down so as to be at right angles with the jaw ; the lower lip is 

 necessarily drawn downwards and backwards, so as to widen the orifice of the mouth, 

 and the profile of the fish, with the process projecting downwards, is then such as is 

 seen in the dried specimen. At the same time as the opening of the mouth is en- 

 larged, the capacity of the throat is widened. The long Ibrk or process consists of 



