FISIIKS — WAITK. 47 



coiunioii with most juveniles of the genus it is quite smooth ; the 

 tail measures more than twice the length of the disc. Dark 

 olive-brown above, the under surface and the lower base of the 

 tail is whitish, the margins of the disc brown. The absence of a 

 membraneous expansion above the tail places the species in the 

 subgenus Ilcmitri/iid)!., Midi, and Henle. 



Familij MYLIOBATID^. 



MYLIOBATIS, Dumtril. 



MYLIOBATIS AUSTRALIA, Madeay. 



Eagle Ray. 



.Myliohatis australis, Macl., Proc. Linn. Soc. N.S.W., vi., 1881, 

 p. 380. McCoy, Prod. Zool. Vict., Dec. vii., 1882, pi. Ixiii. 



Stations 1, 10, 20, 21, 22, 23, 24, 25, 26, 

 50,51, 52, 53, 54, 58. 



McCoy has compared this species with Myliobatis nieahofi, 

 Bl. Schn., and remarked that among other features it differs 

 therefrom by the spotted instead of striped disposition of the 

 blue colour. This colouration is variable, and is much affected 

 by age, the younger examples being, as Giinther remarks,* more 

 ornamental in colouration. All the specimens brought home are 

 small, measuring less than two feet across the disc ; in such, the 

 markings are very distinct and in the form of lines and spots, the 

 anterior lines are the first to break up, and the posterior ones are 

 much more persistent. In some larger examples obtained, beyond 

 the general disposition of the spots — lines did not occur — such 

 resembled the markings as figured by McCoy. 



Another character emphasised hj this author is that of the 

 teeth, and he compares the width of the median lamellae with their 

 length, remarking that whereas the proportions in M. nie^ihofi 

 are 3 or 3^ to 1, in M. australis the figures are 7|^ to 1. This 

 again does not appear to be a very stable character, for as Giinther 

 also remarks :— "The young differ much from the adult, having 

 no median series of larger teeth, but all the teeth of equal size 

 and regularly sexangular." The proportions in our examples are 

 about 5 to 1, or midway between those of the two species 

 mentioned. The width of the disc is also intermediate, being 

 proportionately less than in M. nieuhofi, and more than in M. 

 australis. 



Under these circumstances I strongly incline to regard these 

 species as identical, 21. nieuhofi having priority ; but in the absence 



* Giinther— Study of Fishes, 1880, p. 345. 



