290 Sir J. Richardson on Atistralian Fish. 



about six slender lines on the gill-cover, which are thickened on the 

 suprascapular region. The body is traversed by seven or eight rows 

 of short blue lines, which on the tail are superseded in part by dots. 

 The dorsal and anal have about three rows of these short lines, and 

 the caudal, wliich is reddish-orange, is streaked longitudinally with 

 blue. The pectoral and ventrals are flesh-coloured. 

 Length of specimen 12^ inches. 



Olisthops, Richardson. 



{Olisthops, ex dXiirdqpus, lubricus, et w\\j, vultus.) 



Genus generis Odaeis affine. Caput totum cute lubrica, esqua- 

 mosa tectum (squamulae quatuor tantum inconspicuis regioni supra- 

 scapulari utrinque insidentes) . Labia simplicia cum cute faciei con- 

 tinua, labia preorbitalia nulla. Dentes cum ossibus Imiatis pre- 

 maxillaribus mandibulisque, modb Scarorum ferruminati. [Ossa pha- 

 ryngea ab exemplaribus nostris excisa, hiuc nobis ignota.] Squamae 

 cyloidese. Linea lateralis simplex, e tubulis rectis facta, continua ; 

 antice arcuata, postice recta. Pinna dorsi unica, prope humerum 

 incipiens, in parte spinosa, modo proprio, emarginata ; radiis spino- 

 sis apicibus flexilibus. Pinnae ventrales sub axillis pectoralium po- 

 sitse. Membrana branchiostega in gutture continua, utrinque radiis 

 quatuor sustentata. 



The general form of this fish has been known to me for some years 

 by the accurate drawing of Mr. Neill. It is an inhabitant of King 

 George's Sound in Australia, where it is recognised by the natives 

 \inder the name of " Toobitoet," or " Toobitooit," and it is said to 

 inhabit rocky places and to be rarely captured. In the construction 

 of its jaws and in general form it approacltes most nearly to Odax, 

 but it differs from that genus, and still more from Scarus, in the want 

 of scales on the head, the single lips, and in the unusual form of the 

 dorsal. The subjoined description is drawn up from a specimen pre- 

 pared by Mr. Neill, which I have lately had an opportunity of in- 

 specting. 



In the shape of the jaws Olisthoj)s resembles several species of Odax 

 which inhabit the Australian seas, but does not agree altogether with 

 the account of the dentition of that genus as given in the ' Histoire 

 des Poissons' (xiv. p. 299), nor with the drawing of the jaws of Odax 

 pullus (op. cit. pi. 408. f. 2). 



The jaws of Odax, says M. Valenciennes, are composed, as in Sca- 

 rus, of an assemblage of small teeth arranged in a quincuncial order 

 and intimately soldered together, forming on each side a single body, 

 whose cutting edge is crenulated ; but these jaws are neither so broad 

 nor so convex as in Scarus, and are entirely covered by the lips. They 

 differ from those of Scarus in that the teeth form two spoon-bowls at 

 the end of the mouth in front of the spinous points which crown the 

 teeth of the jaw. Olisthops and several Odaces want these poste- 

 rior marginal toothlets, the spoon-shaped masses constituting the en- 

 tire dental process of the jaw, and showing their origin merely by the 

 reflections of the incorporated, minute pearly quincuncial teeth, so 



