i ., [[PrOc. Eoy. Soc. Victoria,, 34 (N.S.), Pt. I., 1921]. 



Art. III. — The Specific Name of the Australian Atiiria 

 and its Distribution. 



By FREDERICK CHAPMAN, A.L.S. 



^(Palaeontoloo^lst to the National Mviseuuo, and Lecturer on Palaeontology 

 at the Melbourne University.) 



(With Text Figure.) 



[Read 12th May, 1921]. 



The Specific Name. 



The unrivalled experience and wide acquaintance of the Ter- 

 .tiary mollusca which my friend, Mr. R. Bullen Newton, pos- 

 sesses would naturally forbid me to question his decision that 

 .the Australian Atiiria australis is identical with the European 

 Atiiria aturi, had it not happened that already 1 have shown, •■ 

 at least to my own satisfaction, that the species are entirely dis- 

 tinct. 



Mr. Newton has recently published^ an account of a sand- 

 stone cast of an Atiiria from Western Australia, lately acquired 

 by the British Museum, and bases upon this and a comparison 

 of presumably the two specimens recorded from the British 

 Museum collection,'^ a conclusion as to their identity. The dif- 

 ferences between these forms, the Australian and the European, 

 1 have already pointed out,"^ though this seems to have been 

 overlooked by Mr. Newton. These differences are as follows : — 



'' (1) The Australian shells are more compressed. 

 (2) The septa and growth-lines are more strongly recurved 



towards the periphery. 

 (3) The siphuncular orifice is larger."^ 



In the same paper I also remarked as follows : — 



** In view of the above-named characters, which are constant 

 so far as my own observations go, there are justifiable grounds 

 for keeping the Australian form as a distinct species, at the 

 same time bearing in mind that its relationship is nearest Aturia 

 aturi. . . . Probably did the London Museum [British] 



1. Proc. R. See. Vict., Vol. xxvii. (N.S.), pt. ii., 1915, pp. 350-353, pi. iii. 

 rflgs. 1, 2. 



2. Proc. Malac. Soc., Vol. xiii., Oct.. 1919, pp. 160-167, pi. v. 



3. Cat. Foss. Cephalopoda, Brit. Mus., pt. ii., 1891, p. 355. 



4. Log. supra cit., p. 352. 



.5. I find, however, that this is not an invariable character. 



