304 PLACTJNANOMIA. 



striated, adjacent to the anterior margin of -which is a small 

 conspicuous pedal scar." He refers this fossil to the recent F. tone 

 with some hesitation. 



Dimensions. — Height 40mm.; length 40mm. 



Form, and Loc. — Miocene : Muddy Creek, Yictoria. 



L. 6583. Unattached valve, much worn. Purchased. 



L. 9831. Two examples of the unattached valve. Purchased. 



Placunanomia sella, Tate. 



1886. Placimanomia sella, Tate, Trans. Roy. Soc. South Aust. vol. viii. 



p. 102, pi. V. figs. \a-c. 

 1893. Tlacunanomia sella, Tate and Dennant, id. vol. xvii. pt. 1, p. 223. 

 1896. Placunanomia sella, Pritchard, Proc. Roy. Soc. Vict. vol. viii. n.s. 



p. 127. 



Shell ovate, thin, inequivalve, umhones depressed, marginal, 

 overhanging. Left valve hent, slightly convex, margin undulating ; 

 muscular impressions large, two in number, towards the centre, 

 comprised within a linear, circumscribed, elongate area. Eight 

 valve irregularly concave, perforation large, elongate, muscle- 

 markings prominent. Exterior of both valves ornamented with 

 numerous radial threads and lamellae of growth. 



The surface ornament and the ovate or suborbicular shape of tlie 

 shell serve to readily distinguish this species from P. ione. 



Dimensions. — Height 27 mm. ; length 25 mm. 



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



L. 4817. Two specimens of the adult, both valves. 



Presented hj John Dennant, Esq. 



L. 9842. Examples of both valves. Purchased. 



Placunanomia elyros, Gray (sp.). 



1849. Anomia elyros. Gray, Proc. Zool. Soc. p. 118, pi. iv. fig. 1. 



1859. Anomia elyros, Reeve, Conch. Icon. vol. xi. pi. i. fig. 3 ; pi. ii. fig. 9. 



The specimens in the Museum collection now assigned to this 

 species are more finely plicated exteriorly than are the Australian 

 examples the writer has seen : the shell is so variable that this 

 IS^ew Zealand form might well be included in P. elyros in 

 preference to being relegated to a new species. The attached 



