12 SUPPLEMENT TO THE 



DESCRIPTIONS OF SPECIES. 



Genus — Waldheimia, Ki7iff, 1850. 



1. Waldheimia (vel Macandrevia) Whidbornei, Bav. Dev. Mon., PI. I, figs. 1 — 8; 



and Dev. Sup., PL I. 

 figs. 3, 4. 



Terebratula sacculus var. 1 Dav. Dev. Mon., p. 6, PI. I, figs. 1 — 8 (not A. sacculus 



Martin), 1864. 



Shell longitudinally oval, rather broader anteriorly, more attenuated posteriorly, 

 slightly rounded in front. Valves evenly convex, without fold or sinus. Ventral valve 

 the deepest ; beak incurved and truncated by a small circular foramen ; beak-ridges 

 moderately defined, deltidium small. Surface smooth, finely punctated. In the 

 interior of the dorsal valve the loop is nearly three lines in length, and rather more than 

 half the length of the dorsal valve. Beyond their attachment to the hinge-plate the lamellae 

 widen into two small crural processes. They then take a gentle outward curve, and after- 

 wards approach each other again by a slight curve before forming the reflected part of the 

 loop. Dimensions variable — 



Length 9, width 6, depth 5 lines. 



Obs. — When describing this species at page G of the ' Devonian Monograph,' I felt very 

 uncertain with respect to my identification ; being totally unacquainted with its internal 

 arrangements I could arrive at no definite conclusions. Some time in 1880 Mr. G. P. 

 Whidborne, an acute and careful observer, expressed to me his suspicion that the shell under 

 description would prove itself to be specifically distinct from Martin's Tereb. sacculus. 

 Specimens of both were consequently placed into the hands of the Rev. Norman Glass for 

 internal examination, and he soon was able to show that their loops differed materially. 

 In Ter. sacculus it is similar to that of Terebratula, while in Wald. Whidbornei it is long 

 and reflected as in Waldheimia. In external shape the species under description 

 bears much resemblance to similar-sized examples of Wald. cranium, and its loop is 

 much the same as that of the recent species. 



Prof. King, in 1859, proposed a genus Macandrevia for W. cranium and similar 

 shells, and that genus is maintained by Mr. Douville in his memoir, " Sur quelques 

 genres de Brachiopodes," &c. (' Bull. Soc. Geol. de France,' 3rd series, vol. vii, 1879); 



