126 DR. RICHARDSON'S DESCRIPTION OF AUSTRALIAN FISH. 



with a loose tip, but there is no vestige of similar plates exterior to these fins, though, as 

 the specimens have lost a few scales in their long voyage, there is some uncertainty on 

 this point. [Mugil curvidens wants these appendages, and they are more or less re- 

 stricted in other species.] There are traces of scaly stripes between the rays of all the 

 fins but the first dorsal. [M. cryptocheilos, cure'ma, pefrosus, Diissumieri, melanopterus 

 and carinatus are described in the ' Histoire des Poissons ' as having scaly dorsals and 

 anals.] 



The gill-membrane is so narrow that the branchial ribs could not be counted without 

 dissection. The pectoral is obliquely pointed, its upper rays being longer, and the 

 lower ones very short. The second dorsal is supported by ten rays, of which the first, 

 which lies closely against the second, is the only simple one : it looks like a spinous 

 ray, but with a good eye-glass the articulations of its tip become visible. The first 

 anal spine is scarcely perceptible ; the third is half the length of the soft ray which suc- 

 ceeds it ; all the three spines are pungent : the margin of the fin is concave. The scaly 

 fillet lying between the pectorals covers a membranous fold which binds both fins down 

 to the abdomen. The caudal is forked. 



Colour. — The scales have a golden lustre ; but the specimens retain no traces of lines 

 or shades of colour, nor any remains of spots on the pectorals or other fins. 



Anatomy. — The large air-bladder is as long as the abdomen, but its exact form was 

 not ascertained. Like the peritoneum, it is covered by a blackish pigment. The 

 alimentary canal descends from the pharynx in a tube nearly of equal width, till it 

 forms a projection of the stomach similar in size and form to the pyloric C£eca. To the 

 side of this 'cul de sac' there is attached the globular, gizzard-like part of the stomach, 

 which is coarsely plaited interiorly, the folds becoming much finer as they extend up- 

 wards into the oesophagus. The pylorus is surrounded by a narrow but distinct villous 

 valve that projects into the gut, but there are no long filaments springing from it as in 

 Mugil cephalus. The succeeding part of the gut is somewhat dilated, and its interior is 

 finely reticulated with villous rugse. The three caeca ' open into this wider part of the 

 canal immediately below the pylorus : the canal narrows below, the rugse soon disap- 

 pear, and the membranes of the gut become more delicate. The rectum is a little wider ; 

 but I could detect no papillce in it, nor in the small gut, nor any cilia on the thickened 

 ring which marks the junction of the two. The rectum alone shows faint and very 

 delicate reticulations on its inner coat. On each side of the upper surface of the pha- 

 rynx there is a soft, spongy, oval cushion, which is studded with soft warts intermixed 

 with minute teeth ; before this there are two small lobes that represent the foremost 

 pair of pharyngeal bones. At the root of the tongue there is a very minute cluster of 

 teeth, but the narrow isthmus of the branchial arches, anterior to the lower pharyngeal 

 bones, is flat and smooth. These bones oppose long, narrow, nearly flat, dental surfaces 



' Mugil cephalus, Dajaus monticola, and many other MuUets have two C8eca ; others have six, seven, eight, ten, 

 or seventeen ; but none are described in the ' Histoire des Poissons ' as having three. 



