347 



Tamily NUCULID^. 



Genus NTJCULA, Lamarck, 

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



Shell oval, or elongate, equivalve, inequilateral, posterior side 

 very short ; umbones inclined posteriorly ; surface smooth or 

 striated ; hinge angulate ; ligamental pit internal, triangular, and 

 on each side are developed numerous compressed, sharp teeth ; 

 interior of the valves nacreous, adductor impressions subequal ; 

 pallial line simple. 



Type. — Area nucleus, Linnaeus. 



Nucula tenisoni, Pritchard. 



1877. NucuJa tumida, Tenison-Woods, Pap. Eoy. Soc. Tas. 1876, p. Ill 



{non Hinds nee Philippi). 



1878, Kucida grayi, Tenison-Woods, id. 1877, p. 55 [non D'Orbigny). 

 1886. Kucula tumida, Tate, Trans. Eoy. Soc. South Aust. vol. viii. p. 127, 



pi. vi. figs. Gar-b. 

 1893. Nucula tumida, Tate and Dennant, id. vol. xvii. pt. 1, p. 224. 



1895. Numla tumida, Tate and Dennant, id. vol. six. pt. 1, p. 112. 



1896. Nucula tenisoni, Pritchard, Proc. Eoy. Soc. Vict. vol. viii. n.s. p. 128. 



Shell solid, tumid, smooth ; surface with several concentric 

 growth-folds, lunule conspicuous ; margin acute, not crenulated ; 

 " hinge teeth diverging progressively in an increasing series, 

 interrupted by a narrow, deep ligamental pit, which is obliquely 

 produced" {Tate) ; the posterior row has about eight teeth, and the 

 anterior thirty. 



Mr. 6. B. Pritchard {op. cit. supra, pp. 128-130), has treated 

 of the synonymy at some length ; the present writer has not the 

 materials to enable him to express an opinion as to whether 

 iV. tumida and N. grayi, Tenison-Woods, are, or are not, identical. 



Dimensions. — Height 17 mm.; length 22 mm. 



Form, and Loc. — Eocene : Tasmania and Victoria. 



83995. Right valve ; from Table Cape. Purchased. 



L. 4808. Several examples of both valves ; from Muddy Creek. 



Presented ly John Dennant, Fsq. 



L. 9827. Series illustrating stages of growth; from Muddy 

 Creek. Purchased. 



