536 STUDIES ON AUSTRALIAN MOLLUSCA, IX., 



Superficially the novelty has a general resemblance to the 

 European A. tornatilis Linn. From A. austrinus Watson, the 

 only species yet recorded from this coast, it is easily separated by 

 its large size, different colour and sculpture. It is also twice 

 the size of any of the genus described from Australian Tertiary 

 beds. 



There is a closely allied species from 110 fathoms off the Great 

 Barrier Island, New Zealand, which my friends Messrs. R. 

 Murdoch and H. Suter are about to describe as A. cratericulatus. 

 The New Zealand shell differs by being much smaller, with 

 sharper sculpture, the grooves being broader and deeper and 

 crossed by more distant and elevated threads. 



Tethys norfolkensis Sowerby. 

 (Plate xxxiii., figs. 33, 34). 

 Aplysia norfolkensis Sowerby, Conch. Icon., xvii., 1869, pi. x., 

 fig.42. 



This species has not been found, as the name falsely implies, at 

 Norfolk Island. The type was taken by Brazier in Sydney 

 Harbour. As the species has hitherto rested on the shell alone, 

 I take the opportunity of supplying a figure and description of an 

 animal procured during an excursion of the Field Naturalists' Club 

 to Balmoral. 



The animal in extension was about 40mm. long, but, as its 

 shell was smaller than others I have seen, I suppose it to be a 

 small specimen. In colour it was the brown of the kelp weed, 

 spotted with scattered white dots, and edged with black along 

 the margins of the lobes and on the tentacles. Parapodial lobes 

 short, united behind, with digitate margin, free from the siphon. 

 The crown of the shell protruded through an opening in the 

 centre of the mantle. On the hind right side the mantle is 

 produced into a large orifice enclosed by upstanding lobes. 

 From the shell the mantle is rayed with brown and white. The 

 branchiae in life are entirely concealed. Tail rather long. The 

 animal kept in confinement did not use its lobes for swimming, 

 and emitted purple when annoyed. 



