BY J. DOUGLAS OGILBY. 1*27 



remove Castelnau's genus to its true systematic position; however, 

 as was kind!}' pointed out to me by Dr. (rill, Steindachner had 

 previously recognised the close relationship of these two genei^a 

 (Zool. Jahresb. 1879, p. 1061). 



Mr. Zietz, the latest writer on the sul)ject, who has followed 

 Steindachner and me in making Aristeus synonymous with 

 Nematocentris, refrains from enlightening us as to his views of the 

 systematic affinities of this genus; two new species from Central 

 Australia are described by this author, who places them (Horn 

 Exped. Centr. Austr. pp. 178-9) between the Theraponids and 

 the Eleotrine Gobiids, below which G'obivs itself is ranked, thus 

 securing so wide a margin for selection that we are left in doubt 

 as to the family in which he is in favour of leaving it, though we 

 would be justified in inferring that he considers Castelnau correct 

 in allying Aristeus — and, therefore, by his" own admission of the 

 identity of the two genera JVematncentris — with Eleotris, since by 

 no jiossibility could the percesocoid fishes be so placed. 



Curiousl}' enough Castelnau himself, in the same pamphlet in 

 which the diagnosis of JVeoafheiina is published, described j^et 

 another new genus as Airla, of the close relationship of which to 

 liJiombatractus I shall have something to say further on, and 

 places it " with considerable doubt in the family of the Percichv." 

 that is to say, in that section of Giinther's Fercidce, which we 

 should now call Apogo-xvlcn or C hil o dipt er 'nice; there it is left 

 without comment by Maclea}-. 



Prior, however, to the publication of Castelnau's paper. Dr. 

 Peters had already assigned to his genus Nemntoceairh a position 

 near to the Apogons, although the species on which his diagnosis 

 was formed had been described many years previously by 

 Richardson as Atherina niyrans, and holds a place in Giinther's 

 Catalogue as Atheriniclotliys nigrans\ Kner and Steindachner, how- 

 ever, in the same year point out the affinity existing between 

 Nematocentris and the Atherinids, though none of these authors 

 app3ar to have suspscted the identity of their respective species 

 with that of Richardson. 



