110 Proceedings of the Royal Society of Victoria. 



already made. Possibly several described varieties are present, 

 including var. torosa, Jones.^ Many of the specimens from the 

 Silurian of Victoria are represented by hollow moulds of the 

 valves, from which it is possible to obtain a very faithful 

 impression in wax. In others, again, we have a cast of the 

 interior of the valve in relief, the shell having been dissolved 

 completely away. 



Locality a?id Horizon. — Junction of Woori-Yallock and Yarra 

 Rivers. Collected by Geol. Surv. Vict. B. 23. [431-6] 

 Silurian. 



Beyrichia kloedeni, McCoy, var. granulatn, Jones. 

 (PI. XVI., Fig. 8). 



Jones, 1855, Ann. Mag. Nat. Hist., ser. 2, vol. xvi., p. 166, pi. 

 vi., fig. 9. Jones and Holl, 1886, ibid., ser. 5, vol. xvii., p. 350, 

 pi. xii., fig. 2. 



Several examples of the above variety were found amongst a 

 collection of specimens labelled Beyrichia in the National 

 Museum, one of which (the specimen now figured) shows the 

 anterior lobe in the hypertrophied condition. [-I-IO]. The surface 

 of the valve shows a certain amount of granulation like the 

 variety figured by Prof. Rupert Jones. Our specimen seems 

 to have been slightly crushed between the posterior and middle 

 lobes. 



Locality and Horizon. — Junction of Woori-Yallock and Yarra 

 Rivers, east of Melbourne. Collected by Geol. Surv. Vict. B. 

 23. [437-40]. Silurian. 



Beyrichia wooriyailockensis, sp. nov. (PI. XVI., Fig. 6). 



Description. — Valves sub-obloug, with three unequal lobes; the 

 middle lobe is short, extending only halfway to the ventral edge 

 of the valve, freely coalescing with the ventral ends of the 

 anterior and posterior lobes ; anterior lobe full, but not much 

 longer than the mid<lle lobe ; the hind lobe broader and flatter at 

 the dorsal edge of the valve than the other two, and modified by 

 a vertical sulcus to nearly one-half its length ; ends of lobes 



1 Ann. Mag. Nat. Hist., series 2, vol. xvi., p. 167, pi. vi., figs. 10, 11, ? 12. 



