855 



ON A COLLECTION OF FOSSIL POLYPLACOFIIORA 

 FROM NORTH-WESTERN TASMANIA, WITH DE- 

 SCRIPTIONS OF THREE NEW SPECIES. 



[mollusca.] 



By a. F. Basset Hull. 



Plate xciv. 



I have had the privilege of examining a number of fossil valves 

 belonging to the genera Chiton, Lorica, and Loricella, collected 

 by Messrs. E. D. and R. N. Atkinson from the well-known beds 

 between Wynyard and Table Cape, Tasmania. 



This collection is remarkable for the number of valves of Lorica 

 duniana Hull,* associated with valves of no less than three 

 hitherto undescribed species of Loricella. One anterior valve of 

 Lorica duniana (which I described from a median valve) is in- 

 cluded. This specimen is imperfect and greatly eroded, but 

 sufficient of the sculpture remains to show that it consists of 

 numerous radiating riblets, low, and broken transversely by 

 irregular grooves. One median valve of Chiton fossicius Ashby 

 it Torr,t was with the collection. The type-locality of this 

 species is Table Cape. 



The occurrence of no less than three strongly marked species 

 of the genus Loricella in the Table Cape beds, and another species 

 (L. gigantea Ashby <k. Torr) in the Mornington (Victoria; beds, 

 is particularly interesting, in view^ of the fact that this genus is 

 represented by a single living species, L. a^z^asi Adams <t Angas, 

 which is common to South Australia, Tasmania, Victoria, and 

 New South Wales. The fossils all differ from the living repre- 

 sentative of this dwindling genus, the sculpture varying to a 

 marked degree. The closely allied genus, Lorica, is also repre- 

 sented by three species in these beds, while one only, L. volvox 

 Reeve, is now extant. 



* These Proceedings, xxxv., p. 264(1910). 

 t Trans. Roy. Soc. S. A., 1901, p.UO. 



