﻿102 ME. S. S. BTJCKMAN OX CEKTAIN JTJKASSIC [Feb. I9IO, 



Teeebratula aeenaeia, sp. nov. (PI. XII, figs. 17 & 18.) 



Description. — An obovate, ineqnigibbous, biplicate Tere- 

 bratulid. Dorsal valve flattish, ventral valve gibbous, less so 

 anteriorly. Side-margin curved, and anterior margin producing a 

 distinct M fold. Beak sbort, stout, with indistinct beak-ridges ; 

 foramen somewhat small, with a labiate extension almost touching 

 the umbo and hiding the deltidial plates. 



Distinction. — When compared with T. whaddonensis, it is seen 

 to differ in shape and proportions in many respects. T. varicans, 

 Rothpletz 1 is a smaller, narrower, and for its age more plicate species ; 

 other figures differ still more. 



Locality, etc. — In the same beds and localities as T. whaddon- 

 ensis ; but scarce. 



Aulacothyeis CTJCULLATA, nom. nov. (PI. XII, figs. 1 & 2.) 



1882. Shells like Waldlieimia meriani, S. Buckman, Proc. Dorset Nat. Hist. & 

 Ant. F.-C. vol. iv, p. 34. 



Description. — A broad, short naviculoid, with a deep sulcus 

 in the dorsal valve, and an elevated carina in the ventral. Beak 

 curved over like a monk's cowl, strong beak-ridges, and a small 

 foramen. 



Distinction. — Resembles a dwarf Aulacotliyris meriani (Oppel), 

 but is much more sulcate for its size. Is a larger and more 

 sulcate shell than A. doultingensis, Richardson, its possible ancestor. 



Locality, etc. — In brown clay on the top of the zigzag bed of 

 Grange Quarry, Broad Windsor (Dorset) ; not uncommon. Its date 

 is therefore early fuscce hemera, and it should be found in the Scroti 

 or overlying Fullers' Earth Clay at Burton Bradstock. 



Zeilleria whaddonensis, sp. nov. (PI. XII, figs. 13 & 14.) 



Description. — An elliptical, tumid, smooth Dallinine, with 

 an almost even margin, a tumid ventral valve posteriorly, a 

 stout curved-over beak with strong ridges, a small incomplete 

 foramen, and narrow deltidial plates. 



Distinction. — Zeilleria opjjeli, S. Buckman, 2 is a more circular 

 and 'flatter shell, lacking the elongate character : that form agrees 

 more with the young stage of the present shell. 



Locality, etc. — Stoke Knap (Whaddon Hill) and Chideock 

 Quarry Hill (Dorset), in the sandy grits with T. whaddonensis. 

 Z. oppeli characterizes the Rusty Bed of Burton (see section, p. 74). 

 The species now described might be expected in the same place or 

 just below. 



1 ' G-eol.-pal. Monogr. Vilser Alpen' Palseontcgraphiea, vol. xxxiii (1886) 

 p. 97 & pi. iv, fig. 3 only. 



2 Quart. Journ. Geol. Soc. vol. Hi (1886) p. 702. 



