McCULLOCH AND WAITE — P'iSHES FROM SOUTH AUSTRALIA 45 



scales: mouth small. ])rotractile : hands of villiform teeth on the jaws; a large 

 ])atch on the vomer, and some on the anterior part of each palatine ; tongue 

 smooth : preorbital entire or denticulate, the other bones smooth ; operculum with 

 two flat spines: suborbitals ligamentous: cheeks, opercles. nape and interorbital 

 space scaly, snout and lower jaw naked : mucigerous canals and pores are present 

 on the mandible, preopercular margin, snout, upper surface of the head, and 

 above the opercles : nostrils large and widely separate : gill-membranes narrowly 

 united, partly free from the isthmus : pseudobranchiae well developed, gill-rakers 

 moderate, few in number; \-\i branchiostegals. Dorsal fins connected at the 

 base, the spinous portion longer than the soft; D.vi-ix ; i, 8-10; A.iii. 6-8: ventral, 

 with a strong spine, inserted behind the pectoral ; caudal rounded. Premaxillary 

 processes not reaching the frontals; supraoccipital crest not extending on tlie 

 upper surface of the cranium: no parietal crests. Vertebrae 28 (12-13-1- 1 5-16). 

 Affinities. According to Regan, this genus is allied to Kiililia, in the family 

 Centrarchidae. 



Distribution. Southern and Western Australia, and Tasmania. 

 Synonytny. A careful comparison of the genotypes, A^. australis, 

 P. obscunts, M. yarrac. and P.. vittaia. shows them to be very closely allied, and 

 evidently congeneric. Giinther's original definition of Nannoperca included some 

 important errors which have causefl some confusion : he observed no lateral line, 

 whereas his figure shows a very distinct canal, which, however, is quite different 

 from what is actually found in the genus : the entirety or serrature of the pre- 

 orbital bone in N. australis and A'^. vittata affords a generic distinction according 

 to Regan, but a somewhat intermediate form is found in TV. obscura; he also found 

 the interorbital area naked in Nannoperca and scaly in Pdclia, but we find the 

 scales similarly disposed in all our examples of both genera. 



KEY TO THE SPECIES OF NANNOPERCA. 

 a. Preorbital rounded, entire ... ... ... Subgenus. Nannoperca 



h. Third anal spine not longer than the second: 

 maxillary reaching to below the orbital 

 margin: vi-vii, rarely viii spines in the first 

 dorsal ... ... ... .-. australis and tasiinmiae 



aa. Preorbital angular, serrated ... ... ... Subgenus Edelia 



c. Third anal spine longer than the second: 

 maxillary reaching to below the orbital 

 margin: viii-ix spines in the first dorsal ... obscura 

 cc. Third anal spine not longer than the second : 

 maxillary not reaching the orbit: vii-viii 

 spines in the first dorsal ... ... vittata 



