THE BRITISH FOSSIL BRACHIOPODA. 265 



Obs. — The very regularly equal-sided shape of this small specimen, so completely 

 resembles that of a Brachiopod, that it led me to place it provisionally among the Tere- 

 bratula. Mr. E. Provis assures me that similar but unequal-sided specimens of the same 

 species, and also from the Middle Lias at Munger Quarry, Radstock, are in the Bath 

 Museum, labelled Cardita mufticostata, and consequently placed among the Lamelli- 

 branchiata. More specimens will, however, have to be examined before the shell under 

 description can be correctly classed. 



20. Terebratula, sp. Dav., Appendix to Supplements, Vol. V, PI. XX, fig. 16, 

 16 a, b. 



Shell transversely oval, widest posteriorly, rounded anteriorly. Dorsal valve very 

 slightly and evenly convex, much flattened, with or without a very shallow median 

 depression on the anterior half of the valve. Ventral valve moderately convex ; beak in- 

 curved and truncated by a largish foramen touching the umbo of the dorsal valve, and 

 laterally margined by small deltidial plates ; beak ridges sharply defined. Surface 

 smooth, marked by a few concentric lines of growth. Interior not known. 

 Length 1 inch 9 lines, breadth 1 inch 10 lines, depth 8 lines. 



Obs. — Two examples of this species were obtained by Mr. E. Cleminshaw from the 

 Inferior Oolite {Am. Murc/iisoni-zone) at Corton, near Sherborne, in Somersetshire. 

 They are both remarkable on account of the very great flatness or very slight convexity 

 of their dorsal valves. Not a trace of a median depression was observable in the largest 

 specimen, and only a very slight indication could be seen in the smaller example. 



Feeling uncertain whether this species may not be referable to some of those already 

 described, I have preferred not to give it a specific name. It bears some resemblance to 

 certain forms of Terebratula Omaloqastyr, Zeiten. 



21. Waldheimia Haasi, S. S. Buchnan, MS. Dav., Appendix to the Supplements, 



Vol. V, PL XIX, figs. 11, 11 a, 

 b, c, 12, 12 a. 



Shell sub-pentagonal, longer than wide, broadest posteriorly. Dorsal valve slightly 

 convex laterally ; median sinus concave, commencing at the umbo, widening and 

 deepening as it reaches the front, with sometimes a longitudinal rounded elevation along 

 the middle. Ventral valve convex, much deeper than the dorsal one, with a broad 

 flattened mesial fold slightly depressed along the middle, with large wide concave slopes; 

 beak moderately incurved, truncated by a small circular foramen, and separated from the 

 hinge-line by small deltidial plates ; beak ridges well defined. 

 Length 1 inch, breadth 9 lines, depth 5 lines. 



