DR. RICHARDSON'S DESCRIPTION OF AUSTRALIAN FISH. 89 



aid of a microscope, and when detached and so examined, most of them appear to be 

 oblong, though some are circular, exhibiting concentric lines of structure, entirely de- 

 stitute of any spinous roughness on the surface or margin : some have two or three 

 furrows on the base, with corresponding crenatures on that edge, but very many are 

 entirely devoid of such impressions. The scales, though more widely separated on the 

 belly, are more visible there, owing to the milky appearance of the integuments. There 

 is the same naked space on the thorax, and round the pectoral and ventral fins, as in 

 the other species. The lateral line is formed of little tubular elevations of the integu- 

 ment, and runs nearly straight from beneath the supra-scapulars to the middle of the 

 tail, forking as usual on the base of the caudal fin. 



The second and third spinous rays of the first dorsal are the longest ; the first and 

 fourth are very little shorter ; and the more posterior ones diminish in succession both in 

 height and thickness, the last one being very fine and short. The anterior ones are 

 stout, and the height of the longest is equal to two-thirds of the depth of the body. 

 The lower halves of the first two are serrated anteriorly by the points of appressed 

 spinules, which cannot be seen without the assistance of a lens ; the rays, being near each 

 other at the bases and diverging in a fan-like manner at the tips, resemble those of the 

 Weavers {Trachinus). The dilated summits of the first ten interspinous bones form a 

 shallow furrow for the reception of the spinous dorsal ; the more anterior of these dilated 

 ends or dorsal plates are widest, the others diminishing in succession to the last, which 

 is a mere point. They are a little undulated on the edges, but neither crenated nor spi- 

 nous in the smallest degree. The foremost one has a semicircular outline and forms a 

 flat plate before the first spine, the fish differing in this respect from most other Gur- 

 nards. The second dorsal has none of these plates at its base, which is another pecu- 

 liarity of the species ; it has a slightly arched form, and is supported by twelve articu- 

 lated rays, the first three of which are simple. The anal, commencing opposite to the 

 second dorsal, extends rather further back and has somewhat longer rays. The pec- 

 toral fin is very large with a rounded circumference, and reaches half its own length 

 beyond the anus The three free rays are slender, all of them pass the anus, and the 

 longest, when laid back, just reaches to the tip of the ventral. 



The specimens, after maceration in spirits, show traces of a reddish or purplish tint 

 on the back ; the sides retain a silvery hue, and the belly is whitish. The pectoral fin 

 appears to have been of a purphsh colour on its posterior surface, with small spots of 

 blue among the upper rays, and many yellowish dots below. There are also on that 

 side of the fin two large, contiguous, black, eye-like marks with narrow white borders, 

 one spot between the seventh and eighth rays, and the other between the eighth and 

 ninth ; these spots show imperfectly on the anterior surface when the fin is extended. 

 There is a dark bar across the lower tip of the caudal. 



Anatomical notices. — Descending branch of the stomach as in T. vanessa, but the 



VOL. III. PART I. N 



