2GS APPENDIX TO THE SUPPLEMENTS TO 



26. Waldheimia carinata, Zr/w., var. Crewkerniensis, S. S. Buckman, MS. Dav.,Ap- 



pendix to Supplements, Vol. 

 V, PI. XIX, figs. 8, 8 a. 



Waldheimia carinata is to some extent variable in shape, but as a general rule i3 

 elongated, oval, and rounded in front, as we have represented it in this Appendix, PI. XIX, 

 figs. 1,1 a; its dorsal valve is also more or less concave, or the two longitudinal halves of 

 the valve slope down to a median groove. Sometimes, however, the front line seems to 

 be nearly straight, and in some exceptional examples indented, as in fig. 15 of PI. XXIII 

 of the ' Oolitic and Liassic Supplement,' and in fig. 8, PI. XIX of this Appendix. To 

 this variety Mr. S. S. Buckman has applied the name Crewkerniensis to the form sent 

 to me for description. It occurs in the Inferior Oolite zone of Ammonites Par/cinsoni at 

 Haselbury, near Crewkerne, and Bradford-Abbas, Dorset, as well as at Broadwinsor, in 

 the same county. 



27. Waldheimia bisulcata, S. S. Buckman, M.S. Dav., Appendix to Supplements, 



Vol. V, PI. XIX, figs. 9, 9 a, b, 

 10, 10 a. 



Shell elongated, sub-pentagonal, widest posteriorly, rounded at the sides, indented in 

 front. Dorsal valve moderately convex, and longitudinally divided into two lobes by a 

 deepish depression. Ventral valve deeper and more convex than the dorsal one, 

 posterior half slightly longitudinally keeled, anterior half longitudinally depressed or 

 grooved along the middle ; beak very little incurved ; and truncated by a circular foramen 

 separated from the hinge-line by deltidial plates ; hinge-ridges sharply defined, leaving 

 between them and the hinge-line a flattened space. Surface of valve smooth, marked by 

 concentric lines of growth. 



Length 13, breadth 9, depth G lines. 



05s. — I have seen three or four well-characterised specimens of this species. It is 

 distinguished from Wald. carinata by its almost straight beak, foramen, and deltidium, 

 the beak in Wald. carinata being much incurved ; also by the longitudinal depression or 

 sulcation on the anterior half of the ventral valve. The first specimen was found by 

 Mr. S. S. Buckman in the Inferior Oolite, zone of Am. Par/cinsoni, at Bradford-Abbas, 

 Dorset, and was forwarded to me for description ; a second example was collected in 

 the same locality by the Rev. G. E. Whidborne. 



