333 



Area (Barbatia) crustata, Tate (sp.). 



1886. Barbatia crustata, Tate, Trans. Eoy. Soc. South Aust. vol. viii. 



p. 140, pi. ii. fig. 16. 

 1889. Barbatia crustata, Dennant, id. vol. xi. p. 50. 

 1893. Barbatia crustata, Tate and Dennant, id. vol. xvii. pt. 1, p. 224. 



Shell rliomboidal, though broader posteriorly, medially longi- 

 tudinally depressed, ventral margin sinuated ; hinge-line long, 

 straight ; external ornament consisting of bold, undulating 

 concentric lineations, crossed by longitudinal lines, which become 

 slightly swollen at the points of intersection, and have the 

 appearance of being broken up into short lengths. 



The median depression is characteristic, and serves to distinguish 

 it from the young of A. celleporacea, to which it bears a super- 

 ficial resemblance ; another point of difference, on comparison 

 with that species, is the relatively larger reticulated area between 

 the obtuse keel and the superior border posteriorly in A. crustata. 



Dimetisions. — Height 5 mm. ; length 10 mm. 



Furm. and Loc. — Eocene : Muddy Creek, Victoria. 



L.9909. Several specimens of divers stages of growth. Purchased. 



Area (Barbatia) simulans, Tate (sp.). 



1886. Barbatia simulans, Tate, Trans. Eoy. Soc. South Aust. vol. viii. 



p. 142, pi. xi. fig. 10. 

 1889. Barbatia simulans, Dennant, id. vol. xi. p. 50. 

 1893. Barbatia simulans, Tate and Dennant, id. vol. xvii. pt. 1, p. 224. 



Differs from A. consutilis in being slightly less tumid and 

 relatively longer ; the hinge-line is straighter and longer, and is 

 angulate at both ends. The ornament consists of closely-set 

 radiating costa), each rib of the posterior half being longitudinally 

 sulcated ; growth-lines raised and prominent, causing granulation 

 at the points of intersection with ribs. 



Dimensions. — Height 15 mm. ; length 27 mm. 



Form, and Loc. — Eocene : Muddy Creek, Victoria. 



L. 6596. Examples of both valves. Purchased. 



