150 



Waldheimia Tateana, Woods. Plate vii., ligs. 6a — 6fr ; plate viii., figs. 

 6a — 6c ; plate ix., fig. 2. 



Ref. — Terebratula Tateana, Tenison Woods. 



Trans. Boy. Soc, KS.W., p. 79, f. 5, 1878. 



Shell longitudinally oval, narrow, widest about tlie middle ; 

 sides slightly rounded, nearly straight in front. Valves 

 moderately convex ; surface smooth, marked with a few con- 

 centric stria? of growth. Beak long, narrow, sub-erect, trun- 

 cated by a small circular foramen. 



Shell structure conspicuously punctate under a lens ; pores 

 oval, large, crowded, rather larger than in W. Garibaldiana, 

 but about equal in number. 



The loop offers no particular character ; in a specimen of 

 a total length of '8 inch the loop reaches within 1^ lines of the 

 front. 



Dimensions of a median-sized example. — Length, "8 ; breadth, 

 *55 ; thickness, - 35 inch. 



Observation. — The species exhibits considerable variation; 

 typical specimens are insensibly connected with an ovate form, 

 with rounded sides and front. Another phase of its variability 

 is exhibited by the development of a biplicated front, which 

 gives to the shell a subpentagonal outline. In this latter 

 variety the peduncular valve has a broad shallow depression in 

 the middle line bounded by obtuse folds, corresponding with 

 which, in the brachial valve, is a broad median ridge, bounded 

 by two short almost marginal sulci. There are imperceptible 

 gradations connecting the oval, ovate, and subpentagonal 

 shapes ; the sulcations are always shallow and limited. 



The specimens upon which the species was founded prove 

 on actual examination to be immature examples, though they 

 present the leading characteristics of the adults which I have 

 selected as typical of the species. 



Locality and Horizon. — Tipper Murravian, near Morgan, R. 

 Murray ; Muddy Creek, Hamilton (Tate) ; Table Cape, Tas- 

 mania (Woods). Abundant in the glauconitic limestone to 

 the north of Blanche Point, Aldinga (Tate) ; Muloowortie 

 clays, Yorke's Peninsula (Tepper). 



Waldheimia (?) fimbriata, spec. nov. Plate viii., figs, la— 26. 

 Shell longitudinally ovate, sides and front rounded. Valves 

 moderately convex, the peduncular much the deeper. Surface 

 marked by rounded radial ribs, which extend to about one- 

 third ; about five ribs occupy the front, and a like number on 

 each side ; the rest of the surface is smooth, with a few con- 

 centric striae of growth. Shell structure conspicuously punc- 

 tate under a lens. 



