558 PROCEEDINGS OF THE ACADEMY OF [DeC, 



extended. General form is generally rather more elevated than 

 didyma ampla. The largest example in the Academy's collection has 

 a diameter of 47 mm. 



Type locality, China. Specimens from three sources before us are 

 from China, with one tray labelled Madras. 



Natica intermedia Reclus (not of Philippi, 1836), N. problematica 

 Reeve and N. incisa Dkr. are identical with vesiccdis. 



Folinices papyracea ("Busch," Philippi). 



We have not seen this form, which according to Philippi differs from 

 didyma by its depressed shape and very thin shell. It was known to 

 Phihppi by one specimen measuring about 18 x 20 mm. Natica 

 papyracea major Philippi is a larger form or specimen. 



Polinices aulacoglossa n. sp. PL XXIX, figs, l, 2, 3. 



Shell globose, the contour higher and less broad than in P. didyma 

 and its varieties, solid; light brown or slightly bluish, with an ill- 

 defined white band at the base. Umbilicus much smaller than in 

 P. didyma, very narrow within, half or more covered by the callus, 

 which is dark brown, divided by a submedian transverse sulcus, 

 subtriangular in shape, the upper margin adnate to the end, which pro- 

 jects farther than the free edge of the lobe. Parietal callus heavy, 

 white. Other characters substantially as in P. didyma. 

 Alt. 30^, diam. 31 mm. 



Type locahty, Altona Bay, Williamstown, near Melbourne, Vic- 

 toria. Types No. 94229 A. N. S P., collected by Mr. F. H. Baker. 



Some specimens received from Dr. J. C. Cox are larger, alt. 41 i, 

 diam. 42 mm., otherwise similar. This is apparently the form Hsted 

 by Messrs. Pritchard and Gatliff as Natica didyma Chemn. It is cer- 

 tainly distinct specifically from P. didyma, or any of its subspecies. 



Natica chemnitzii Recluz (not N. chemnitzii Pfr., 1840) seems to be 

 identical with this species, though if so it attains a larger size than 

 any examples we have seen. In any case the name is a homonym 

 and cannot stand. 



Natica tasmanica Tenison-Woods has been placed in the synonymy 

 of P. didyma by Messrs. Pritchard and Gatliff, but Tate and May 

 in their Census of Marine Mollusca of Tasmania (1901) have r tained 

 it distinct, a decision supported by the figure published by them. 

 It is a far smaller species than P. aulacoglossa, alt. 13, diam. 16 mm.; 

 and as Tenison-Woods mentions seeing a number of examples in 

 several collections, it is not likely that he was dealing with young 



