318 SCI^NID^. 



heart-shaped, and occiipies a place beneath the third and fourth 

 vertebrae only ; its point is continued into the middle horn, which in 

 a fish 9 inches long has a diameter of only half a line near its origin ; 

 it runs along the vertebral line of the abdominal cavity, and tapering 

 to a fine point, terminates at the posterior extremity of the ab- 

 domen. Each of the anterior parts of the heart-shaped body is 

 di^^ded into two horns, the posterior of which is turned backwards, 

 long, and forms a tube similar to the median, but with the lumen 

 only half as \vide ; it runs along the side of the latter, in a parallel 

 direction, and terminates in a line point before reaching the extre- 

 mity of the abdomen. The anterior hom is very short, directed for- 

 wards and outwards, and nearly as thick as the median. 



The body of the air-bladder is attached to the fourth vertebra, 

 and the nearest parts of the abdomen, by such a firm and dense 

 cellular tissue, of a white coloiu", that it can scarcely be distiaguished 

 from the membrane of the aii'-bladder. At some distance from the 

 vertebra it becomes gradually thinner, and is lost in the parietal part 

 of the peritoneum. The membrane of the aii'-bladder itself is firm, 

 thick, and of a shining white colour, except in the anterior notch of 

 the heart-shaped body, opposite a pi-ocess arising from the third 

 vertebra. This process forms an arched plate, open at its posterior 

 side, which is directed towards the notch of the aii--bladder ; at the 

 side wdiich is directed towards the belly, it is covered by a thick white 

 membrane, forming a sort of cupola, but with the hinder side open. 

 This cupola fits exactly into the notch of the air-bladder, which is 

 here closed by a very thin membrane only. There is a string roimd 

 the cupola from one anterior hom to the other, to fasten the air- 

 bladder to the process. 



The sl-eleton is not in a good state of presei-vation. The following 

 peculiarities may be observed : — The upper surface of the skull is 

 rather flat on its posterior half, the occipital crest not extending on 

 the crown. The muciferous cavities are well developed, but not very 

 deep ; there is a large elongate central cavity, and six or seven pairs 

 of smaller ones besides. The orbit is smaller than in any of the 

 preceding fishes ; the infi'aorbital arch is broad, and produced back- 

 wards towards the angle of the praeoperculum. The anterior half of 

 the maxillary bone is styliform, the posterior very broad: the iater- 

 maxiUary resembles the maxillary, but is shorter and much more 

 slender ; its posterior processes are unusually broad, as in Micro- 

 pogon. The vomer is concave, tapering posteriorly. The giossohyal 

 styliform. 



There are ten abdominal and nineteen caudal vertebrce, the length 

 of the former portion of the column being to that of the caudal as 

 1 : 2-8. 



No molar teeth on the pharyngeal bones ; several scarcely longer 

 teeth in the outer series of the maxillary bone. 



