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Gatliff had previously sent me a smaller shell of same species 

 that he had also identified with Sykes' type. I felt that to go 

 counter to two such able conchologists needed assurance made 

 doubly sure, and therefore wrote Mr. Kershaw asking that he 

 would be good enough to loan me Sykes' type again with per- 

 mission to disarticulate another valve and clean same, because 

 in its then encrusted and stained condition an element of 

 almost intuition enters into its determination. Mr. Kershaw 

 has sent me the type with the permission asked for. I was 

 disappointed at finding that every valve was fractured, but 

 have successfully disarticulated the second valve, which 

 although considerably broken has sufficient sculpture remain- 

 ing for the purpose. I can, now it is cleaned, authoritatively 

 state that Acanthochiton maughani, Torr and Ashby, is 

 cospecific with Sykes' shell A . pilsbryi, and is therefore a 

 synonym; also that Messrs. Gatliff and Gabriel's shells from 

 Point Cook, Port Phillip, Victoria, are fine specimens of my 

 Port Lincoln shell that I am naming A. gatliffi. I have photo- 

 graphed under a high magnification the cleaned valve of Sykes' 

 type with a corresponding valve of A . maughani from the type 

 locality, Port Victor. This photo is reproduced herein, and 

 will, I trust, demonstrate to the satisfaction of all workers my 

 contention. 



Photography. — I have contended for a long time that for 

 purposes of accurate determination photography should be 

 much safer than the work of an artist however well executed. 

 While good photographs are comparatively easy at low magni- 

 fications, its difficulty is greatly increased under high magni- 

 fication ; this of course is especially the case with the carinated 

 shells of Chitons. Further special methods of lighting have 

 to be made use of. to bring out the sculpture. The species 

 under review has been figured three times — Proc. Mai. Soc, 

 vol. ii., pi. ii., July, 1896, drawn by J. Green for Sykes; 

 again in Trans. Roy. Soc. S. Austr., vol. xxii., 1898, figs. 5, 

 a, b, c, d, and /, pi. vii., under the name of A. maughani, 

 drawn by C. Hedley for Torr and myself ; and lastly, the New 

 South Wales form in Rec. Austr. Mus., vol. vii., No. 4, 1909, 

 figs. 24, 25, 26, and 27, pi. lxxiv., drawn by Miss W. West 

 for Messrs. Hedley and Hull. While the lastnamed figures are 

 beautifully executed and a great advance on earlier attempts, 

 the true character of the remarkable sculpture of the pleural 

 area is not delineated. No further apology is needed for the 

 presentation of the photos of this shell as attached to this 

 paper. It is a satisfaction to have been able to clear up a long 

 standing difficulty, and my thanks are due to Dr. Torr and 

 Messrs. Kershaw, Gatliff, and Gabriel for the examination of 

 material that has helped towards the solution of the problem. 



