164 EDIBLE PISHES OF NEW SOUTH WALES. 



Order 111.— F SYS OS TO ML 



All the fin rays articulated, with the exception o£ the first in the dorsal 

 and pectoral fins, which are frequently more or less ossified (some genera, 

 belonging to the Sternoptychidw, have a rudimentary first dorsal) : ventrals, 

 when present, abdominal and spineless. Airbladder, when present, with a 

 pneumatic duct (except in the Scombresociform Fishes).' 



Family I.-SILURID^. 



Margin of upper jaw formed mainly by the premaxillaries. Maxilla 

 rudimentary, frequently constituting the base of a barbel. Barbels always 

 present. No subopercle. Adipose fin present or absent. Skin scaleless, 

 either smooth or covered with osseous plates, or with small tubercles. Air- 

 bladder, when present, either free in the abdominal cavity, or more or less 

 enclosed in bone, and communicatiug with the organs of hearing through the 

 medium of the auditory ossicles. 



Geographical distribution. — Inhabitants of the fresh waters of the temperate 

 and tropical regions, some species enteriug the sea, but not venturing far 

 from land. 



Group I.— PLOTOSINA. 



Gill-membranes not confluent with the skin of the isthmus, or united to 

 it by a narrow strip only, remaming more or less separate. Dorsal divided 

 into two portioDs; a short anterior with a strong spine, and a long posterior 

 which, like the aual, is confluent with the caudal : ventrals multiradiate. 

 A dendritic postanal apparatus. 



Genus.— CNIDOGLANIS. 



Cnidoglanis, Griinther, Catal. Fish. v. p. 27, 1864. 



Branchiostegals eleven '? Gill-openings wide, the membranes united below 

 the throat, and attached to the i?thmus along the entire median line ; the 

 second and third branchial arches with a series of long cartilaginous pro- 

 cesses covering the base of the gill laminae on the sides facing each other. 

 Plead depressed. Cleft of mouth transverse. Eyes small. Nostrils remote, 

 the anterior tubular and on the front edge of the snout, the posterior simple. 

 Barbels eight. Teeth conical in the upper jaw, molariform on the vomer, 

 and mixed in the lower jaw. Two rayed dorsals, the first with one spine 

 and four or five rays : a pectoral spine. 



Geograpldcal distribution. — Rivers and coasts of Australia. 



CNIDOGLANIS MEGASTOMA. 



JPlotosus megastomus, Eichards. Vov. Erebus & Terror, Fish. p. 31, pi. xxi, ft'. 



1-3. 

 Cnidoglanis mer/astoma, Gnth. Catal. Fish. v. p. 27, ajid Study of Fish. f. 25S ; 



Casteln. Proc. Linn. Soc. N. S. Wales, iii. p. 392; Macleay, Catal, Austr. 



i'ish. ii. p. 14P ; Woods, Fisher. N. S. Wales, p. 81. 

 ChcBroplotosus decemfilis^ Kner, Voy. No vara, P'isch. p. 300, pi. xiii, f. 1. {an 



I'lotosus limbatus, Cuv. & Val. Hist. Nat. Poiss. xv. p. 122.) 



