SEFISION OF AUSTBALIAN THEBAPONS.—OGILBY AND McCULLOCH. :07 



different rivers, the inhabitants of one stream having in the course of ages of isolation 

 developed certain small but constant j)eculiarities, which serve to distinguish them 

 from those of the neighboring watercourses. For instance, the fishes examined from 

 the Upper Burnett differ from those of the Lower Fitzroy as follow, taking the average 

 of all the specimens from either locality : — 



Width of body 2 in its depth ; depth of body 2-53, of caudal pedimcle, which is longer than deep, 

 8, of pectoral fin 4-6 in length of body ; length of snout 3, diameter of eye 3-4, width of 

 interorbit 4-14, longest dorsal spine 1-75, longest anal 2 in length of head ; base of soft anal 

 1-6 in its height . . . . . . . . . . . . Specimens from the Upper Burnett. 



Width of body 2-25 in its depth ; depth of body 2-4, of caudal peduncle, wliich is deeper than long, 

 7-33, of pectoral fin 4-2 in length of body; length of snout 3-23, diameter of eye 3-2, width of 

 interorbit 3-85, longest dorsal spine 1-55, longest anal 1-8 in length of head ; base of soft anal 

 1-35 in its height . . . . . . . . . . . . Specimens from the Lower Fitzroy. 



From none of the other rivers have we a sufficiently large series to permit of 

 generalization, but a pair of fine specimens from the Upper Flinders and Eureka Creek 

 shoAV that these northern mountain forms are even thicker and more slender fishes in 

 comparison with those from the Burnett, their proportions, adhering to the sequence 

 given above, benig 1-83 ; 2-7, 7-5 (though the peduncle is considerably longer than deep) 

 and 4-3 ; the snout even longer, the eye even smaller, the interorbit even narrower, 

 and the anal spine even lower, the measurements being 2-9, 3-55, 4-42, and 2-12. 



Historical : — This pretty little species was originally described by Giinther 

 from " two examples obtained in the Fitzroy River near Rockhampton," sent to the 

 British Museum by Krefft. Three years later Steindachner, under the name Datnia 

 fasciata, described a fish, which was alleged to have come from Port Jackson, and wliich 

 Giinther^ identifies with his Therapon percoides, adding the comment " This species 

 comes from Queensland and not from Port Jackson." After a further lapse of eight 

 years Castelnau, quite independently of Steindachner, described as Therapon fasciatus 

 a specimen of the same fish from Swan River, W.A. One of Castelnau's original 

 specimens is preserved in the Australian Museum. It is dried and somewhat damaged, 

 but does not differ in either structure or color-marking from examples of T. percoides 

 of the same size from the Burnett River, Queensland. Only another three years had 

 passed when the same author again described Giinther's species as Therapon terrce- 

 regince from a small example " taken in one of the northern rivers of Queensland, 

 probably the Fitzroy." In this article he refers to a " Brisbane Museum specimen six 

 inches long from the same river," and incidentally mentions that he believes that his 

 T fasciatus is " confined to the Western Coast of Australia." In the following year, 

 however, he claims to have found several of these fishes in " Mr. Gulliver's collection 

 from the Norman River," but the characters relied on in that paper are those of a 

 ty^:)ical percoides. Macleay, who considered fasciatus to be " a very distinct species," 

 records it from the Palmer River, a mountain tributary of the Mitchell, on the authority 

 of specimens collected by Tenison- Woods, and remarks that it " seems to be confined 

 to the rivers flowing into the Gulf of Carpentaria," entirely overlooking the fact that 

 it was originally described from West Austraha. Liicas as T. fasciatus and Zietz more 

 correctly as T. percoides record the species from streams (Palm and Red Bank Creeks) 

 flowing through the McDonnell Ranges, Central Australia, thus bridging over the space 

 between the eastern and western zones of distribution. Lucas is the first writer to use 

 the preorbital and preopercular denticulations as a means of distinguishing T. fasciatus 

 from T . percoides, but he surely could never have read Giinther's description nor 

 Macleay's copy of it before committing such a blunder. 



2 Zool. Rec, iv, 1867, p. 159. 



