829 



Dimensions. — Height 23 mm. ; length 10'5 mm. 

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



L. 9846. Three examples in which the growth ridges are very- 

 rugose. Purchased. 



Genus MODIOLA, Lamarck {em.). 

 [Mem. Soc. Hist. Nat. Paris, 1799, p. 87.] 



Shell oblong, transverse, inequilateral, equivalve, tumid in front ; 

 umbones obtuse, not terminal ; hinge either without teeth, or with 

 merely a few crenulations anteriorly ; ligament marginal, linear. 



Type. — Mytilus modiolus, Linnaeus. 



Modiola, sp. 



L, 10484. Cast of a large species, off. alhicosta, Lamarck. 

 Miocene : Trelissick, jS'ew Zealand. Sir James Hector Coll. 



L. 10485. Imperfect example of what may possibly be 

 II. australis, Gray, though it is somewhat narrower than are 

 typical specimens. Miocene : Napier, New Zealand. 



Sir James Hector Coll, 



Genus CRENELLA, Brown. 



[Ilhist. Conch. Great Britain, 1827, pi. xxxi. figs. 12-14 ; 2n(l ed. 1844, p. 75, 

 pi. xxiii. figs. 12-14.] 



Myoparo, Lea, Contrib. to Geol. 1833, p. 73. 



Shell oval, or rhomboidal, surface ornamented by longitudinal 

 and concentric striae ; umbones incurved ; cardinal border den- 

 ticulate, the denticles appearing to be the continuation of the 

 crenulations on the margin of the valves; the single denticle 

 present is also crenulated ; interior of the valves nacreous. 



Type. — Mytilus decussatus, Montagu. 



