238 NOTES ON THE BRITISH JURASSIC BRACHIOPODA. 



Further, he not only gave particulars of his own system of 

 classification, but also — only rather too cursorily — of the 

 classification adopted by some of the chief Continental 

 authorities, one of which, M. H. Donville's, is especially 

 interesting. 



In 1879 Douville divided the species included in King's 

 Waldheimia into seven genera, placing them in a distinct 

 family named Waldheimiidge (13, p. 251). The genera are 

 as follows r — 



I. Macandrevia. 

 II. Waldhewiia. 

 III. Neothyris. 

 lY. Plesiothyris. 

 V. Zeilleria. 

 VI. Eudesia. 

 VII. Aulacothyris. 



This sub-division of the genus Waldheimia was based 

 largely upon the presence or absence of rostral septa, and 

 the mode of the plication of the valves. Davidson not only 

 questioned the propriety or necessity of establishing a second 

 family, or even sub-family Waldheimiidae, but also objected 

 to Douville's so-termed genera, considering them as only 

 synonyms of King's genus Waldheimia. In opposition, how- 

 over, to Davidson's opinion, Douville's classification was 

 generally adopted among brachiopodists in this country and 

 on the Continent, so that the generic names Plesiothyi-is, 

 Zeilleria, Eudesia, and Aulacothyris, applied to our Jurassic 

 Waldheimise, are now familiar terms. 



In the same year as the " General Summary " was issued, 

 Dr. Davidson passed away from the scene of his labours, 

 not, however, before he had prepared some excellent notes, 

 which, under the careful editorship of Miss Agnes Crane, 



