BY W. SAVILLE-KENT, F.L.S., F.Z.S., ETC. 43 



were produced just as far as or a little below the lateral line, 

 while a few dark grey or blackish blotches were present on 

 the head. The ground colour of the fins generally was 

 greyish-blue, variously shaded, the free edges of the ventral 

 and anal fins being a pure sky blue ; the anterior or spinous 

 portion of the dorsal fin was variegated with black, the 

 caudal fin was darkest towards its superior and inferior 

 edges and had a narrow posterior margin of pure white. 

 Soon after removal from the water the fish lost all its 

 characteristic markings and faded to a uniform leaden grey. 

 A drawing, illustrating the natural colours of one of the 

 specimens was made from life, and these I have reproduced 

 upon the plaster cast subsequently made from the same fish, 

 and which I also now present to the museum. This cast, in 

 which the precise shape and natural attitude of the living fish 

 has been accurately modelled, will, I trust, prove an acceptable 

 addition to the preserved skin of the original exhibited beside 

 it, but in which, as in all similarly preserved specimens, it has 

 not been found possible to retain either the natural colours 

 or the exact contour of the living fish. 



In communicating this note upon the Butter Fish, 

 GTiilodactylus Mulhallii, I may take the opportunity of 

 recording my opinion that the fish figured and described by 

 Macleay in the proceedings of the Linnsean Society of Kew 

 South Wales (p. 440, pi. xxii) 1884, under the title of 

 Psilocranium Coxii, must be regarded as identical with this 

 species. "With the form given in the illustration quoted, and 

 in all more important details of its diagnosis it essentially 

 agrees. The only feature upon which, so far as I can perceive, 

 its claims to separate generic and sjDecific titles have been 

 founded, is the somewhat smoother surface of the head as 

 compared with the ordinary members of the genus 

 Chilodactylus. This characteristic is, however, equally dis- 

 tinctive of Chilodactylns Mulhallii, as may be verified by its 

 comparison with, say, the more familiar type locally known as 

 the Carp, Chilodactylus Allporti, and of which I also exhibit a 

 coloured plaster cast. The more cylindrical contour of the 

 body, which is quoted by Macleay as substantiating its claim 

 to separate generic distinction, can, I think, scarcely be 

 invested with so important a significance, more especially, as 

 admitted by Macleay in his original description of this type, 

 his diagnosis was formulated from a skin from which the 

 fish's body had been already separated and thrown away. I 

 may add that Mr. Morton, who is personally familiar with the 

 typical examples of Chilodactylus Mulhallii and Psilocranium 

 Coxii preserved in the Sydney Museum, has experienced 

 equal difficulty with myself in detecting any essential points 

 of distinction between these respective types. 



