42 



NOTES ON THE TASMANIAN "BUTTER FISH" 

 (GHILODAGTYLUS MULHALLI), MACLEAY. 



By W. Saville-Kent, F.L.S., F.Z.S., &c., Superintendent 



AND InSPECTOE OF FISHERIES. 



From among the specimens of fish that I have had the 

 pleasure of contributing to the Tasmanian Museum within 

 the last few months, and which have hitherto been unrepre- 

 sented in that institution, I would direct brief attention on 

 th.is occasion to the form known to the local fishermen by 

 the name of the " Butter Fish." This species is evidently 

 identical with the type taken near Port Jackson, and first 

 described by Macleay in the Proceedings of the Linnsean 

 Society of New South Wales, p. 366, 1882, under the title of 

 Ghilodactylus Mulhallii. The probable identity of that species 

 with the Tasmanian Butter Fish has been already recognised 

 by Mr. E. M. Johnston in the appendix to his Catalogue of 

 Tasmanian Fishes, published in the same year. The only 

 point in which these respective forms perceptibly diflfer from 

 one another is afforded by the number of spinous rays, 

 developed in the anal fin. In the Tasmanian variety three 

 such rays were present in each of the several examples that 

 have been examined by Mr. Johnston and myself, while in 

 the Sydney type only two such rays are stated to exist. The 

 third spinous ray is, however, so closely bound up with the 

 succeeding soft rays that it has very probably been over- 

 looked by Macleay. 



The information that is yet wanting to render the descrip- 

 tion of the Butter Fish complete relates to its natural colours. 

 In Mr. Johnston's catalogue, already quoted, it is described 

 as of a " uniform brownish-black," while in Macleay 's 

 diagnosis the distinguishing colours of the body are worded 

 as bluish-grey above and whitish in the ventral region. Both 

 of these descriptions were taken from dead specimens, and 

 neither of them accurately represent the colours of the living 

 fish. In two examples that were brought to the Fisheries 

 establishment at Battery Point in February last, and kept 

 alive there for some time, the body in each instance while 

 agreeing with Macleay's description with respect to its ground 

 tint of bluish-grey, was diversified by as many as seven broad 

 transverse bands or bars of irregular shape, and a blackish. 

 hue which, originating from the summit of the dorsal region, 



