116 DR. RICHARDSON'S DESCRIPTION OF AUSTRALIAN FISH. 



gill-openings, Nemadactylus may appear to be allied to the third or fourth group of 

 scomberoid fishes, as established in the ' Histoire des Poissons' ; but it is separated from 

 them by the simplicity of the pyloric ceeca or pancreatic apparatus. 



Cheilodactylus carponemus has cycloid scales of rather large size and thin texture, and, 

 judging from the descriptions of the other species by Messrs. Cuvier and Valenciennes, 

 they, as well as Cheironemus, depart from the normal characters of their respective 

 famihes in this also, as well as in other peculiarities noticed in the preceding article. 

 Nemadactylus differs still more than these from the percoid or sciaenoid families in 

 the extreme delicacy of its scales, and would appear to be further excluded from 

 the latter by the absence of any appearance of cavernous structure in the cranial 

 bones ; but as Cuvier has in several instances dispensed with this character, and has 

 also admitted Glyphisodon, Atroplus, and Heliases among the Scianoidece, although their 

 gill-covers are unarmed, some naturalists may be inclined to consider that Nemadactylus 

 ought to be ranked in that family also, in which case it will stand in the analytical table 

 of genera after Cheilodactylus ; that is, among those which have a single dorsal, fewer 

 than seven branchial rays, a continuous lateral line, and some simple rays projecting 

 beyond the membrane of the pectoral fin. It may, however, be found more convenient 

 to place these aberrant genera in a separate group, as suggested in the remarks upon 

 Latris. 



Fragments of small Malacostraca were found in the intestines of the specimen de- 

 scribed below ; but I have no information respecting its habits, and can only conjecture 

 that it may be the ' Silver-fish' standing No. 15 in Mr. Lempriere's list. 



Nemadactylus, genus novum. 



Piscis acanthopterygius. Operculum Iseve, inerme. Pinna, genm temporaque esquamo- 

 sse, in dorso pinna unica. Radii pinnae pectoralis inferiores (sex) simplices, quo- 

 rum unus crassior, productus. Costa branchiostega paucse (tres). Intermaxillarum 

 pedunculi breves. Denies gracillimi, minuti, in ambitu oris una serie tantum positi. 

 Fauces, palatum, vomer et lingua glabri. Squama tenerae, leves, infrkque lineam 

 lateralem vix aut ne vix a cute dignoscendae. Caca pylorica pauca (tria vel quatuor). 

 Vertebra circa 34. 

 N. concinnus species unica adhuc detecta. 



Radii.— Br. 3 - 3 ; P. 9 et VI. ; V. 1|5 ; D. 17|28 ; A. 3|15 ; C. 15f . 

 Form. — Much compressed ; the profile broadly elliptical or ovate ; the curve of the 

 back and belly similar, ending in a short tail, whose depth is about one-fourth of that 

 of the body. The body is deepest between the ventrals and fifth dorsal spine, where 

 its height exactly equals one-third of the total length, excluding the caudal fin. It is 

 thickest at the lateral line close to the shoulder, its transverse measurement there being 

 equal to the fourth of the depth ; the sides are much compressed below ; the belly has 

 an acute edge, which continues so to the caudal fin ; and though the back is rounded 



