272 DESCRIPTIONS OP AUSTRALIAN PISHES, 



Family APLOACTID^. 

 Genus Para ploactis Bleeker. 

 Paraploactis thachyderma Bleeker. 



Pm'aploaclis trachyderma Bleeker, Nederl.Tijdschr. Dierkunde, 

 ii., 1865, p.l69. 



Aploactis lichen de Vis, Proc. Linn. Soc. N. S. Wales, ix., 1884, 

 p.460. 



Two specimens received from the Qneensland Museum as 

 Aploactis lichen de Vis, do not differ from Bleeker's description 

 of P. trachyderma. De Vis' type came from Moreton Bay, 

 Queensland, and the Australian Museum specimens were ob- 

 tained at the same locality. 



Genus Aploactis Schlegel. 



Aploactis Schlegel, Fauna Japonica, Poiss., 1843, p.51(^. aspera 

 Richardson). 



Aploactisoma Castelnau, Proc. Zool. Soc. Vict., ii., 1873, p.63 

 {A. schomhurgkii Castelnau). 



Castelnau separated his genus Aploactisoma from Aploactis on 

 account of supposed differences in the dentition. He described 

 the palatines of the typical species, A. schomhurgkii, as covered 

 with minute teeth, whereas they are toothless in Aploactis; he 

 also found a longitudinal ridge at the symphysis of the upper 

 jaw bearing two teeth anteriorly. I have examined several 

 South Australian specimens which are supposed to be A. schom- 

 hurgkii,'* but find no palatine teeth in any, while the longitu- 

 dinal ridge is represented only by a fleshy, toothless tubercle 



I have further compared them with a Japanese example of 



Aploactis aspera, with which they appear to be congeneric; the 



external cephalic structures are somewhat differently formed in 



the two species, but this is probably only of specific importance. 



Aploactis milesii Richardson. 



Aploactis milesii Richardson, Proc. Zool. Soc, 1850, p. 60, PI. i., 

 figs.1-2. 



Aploactisom,a schom,hurgkii Castelnau, Proc. Zool. Soc. Vict., 

 ii., 1873, p.64. 



* See footnote, p. 273. 



