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Notes on South Australian Marine Mollusca, 

 WITH Descriptions of New Species. -Part V. 



By Jos. C. Verco, M.D. (Lond.), F.R.C.S. (Eng.). 



[Read May 7, 1907.] 



During the last session in Adelaide of the Association 

 for the Advancement of Science, Mr. Hedley, of the Austra- 

 lian Museum in Sydney, kindly examined, with me, a number 

 of my South Australian shells, and has since compared them 

 with types in the Sydney Museum. We have thus been able 

 to identify several of our forms. He also took with him all 

 my Pteropods, and returned them named. A trip to the 

 three bays in the South-East of our State — MacDonnell Bay, 

 Guichen Bay, and Lacepede Bay— provided a quantity of 

 minute beach material, which has already proved to be very 

 rich in novelties, and has provided examples of larger shells 

 in such excellent condition as to allow one to speak more 

 certainly upon some previously questionable points. 



Family PATELLID.^, Guilding. 



Genus Patella, Linnaeus. 



P. ustulata, Reeve. 



This species was found in abundance by me this year on 

 the rocks at Western Beach, Robe. -Here and at MacDonnell 

 Bay it was seen in better condition and in greater numbers 

 on the vertical face of the rocks, just above low water, than on 

 the submerged reefs, less eroded and less encrusted. A vari- 

 ant was taken at Robe, suggesting at first a new species, a 

 rather narrow oval shell, with 22 to 24 large, rounded, close- 

 set radial costal, with one feeble or no interstitial riblet. 

 They were found, however, to merge insensibly into the usual 

 forms. 



P. hepatica, Pritchard ct Gatliff. 



At Beachport, on the shore, several dead shells were col- 

 lected, some quite typical, with oblong oval border, and crowd- 

 ed, fine, equal radial riblets. But, though retaining this out- 

 line, their sculpture gradates into the sub-distant costae with 

 intermediate riblets of F. ustulata, Rve. In one individual 

 the sculpture is that of P. hepatica until it is 18 mm. long, 

 when 24 valid white scaly ribs arise. Another shell, measuring 

 41 m.m. by 36 by 20, is provided only with uniform crowded 

 finely-scabrous riblets, combining the sculpture of P. hepatica 

 with the shape and size of the largest of our P. ustulata. 

 Every gradation, too, can be traced between the oblong-oval 

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