336 



Area (Fossularca) dissimilis, Tate (sp.). 



1886. Barbatla dissimilis, Tate, Trans. Roy. Soc. South Aust. vol. viii. 

 p. 140, pi. xi. figs. 4, 6. 



Shell rather tumid, rounded in front, truncated behind ; ventral 

 and dorsal margins nearly parallel ; left valve radially ribbed, 

 crossed by concentric threads, granulated at the points of inter- 

 section; right valve with equidistant concentric folds, pitted between. 



Dimensions. — Height 5 "5 mm. ; length 8 mm. 



Form, and Loc. — Eocene : Aldinga, South Australia. 



L. 9868. Several examples of both valves. Purchased. 



Genus CUCULL^A, Lamarck. 

 [Syst. Anim. sans Vert. 1801, p. 116.] 



Shell rhomboidal, gibbose, almost completely equivalve ; umbones 

 far apart ; area broad, large, having divergent ligament grooves ; 

 cardinal border narrow, anterior and posterior teeth large, oblique, 

 almost horizontal, long, those in the centre short and vertical ; 

 posterior muscular impression large, usually bordered in front 

 by a ridge. 



Type. — C«CM&« auriculifera, Lamarck. 



CucuUsea corioensis, M'Coy. 



1876. Cucullcea corioensis, M'Coy, Prod. Pal. Vict. dec. iii. p. 32, pi. xsvii. 



figs. 3-5J. 

 1886. Cucullcea corioensis, Tate, Trans. Roy. Soc. South Aust. vol. viii. 



p. 144. 

 1888. Ctwulleea corioensis, R. M. Johnston, Geol. Tasmania, p. 235, pl.xxix. 



figs. 4-4a. 

 1893. Cucullcea corioensis, Tate and Dennant, Trans. Roy. Soc. South Aust. 



vol. xvii. pt. 1, p. 224. 

 1896. Cucullcea corioensis, Pritchard, Proc. Roy. Soc. Vict. vol. viii. n.s. 



p. 131. 



This species is allied to the European Eocene C. decussata, 

 Parkinson, but the surface is not so highly sculptured. The shell 

 is very gibbose, umbones prominent and incurved ; area broad, 

 almost flat, with numerous diverging, slightly undulating grooves ; 



