EDMONDIA. 289 



under the same name in pi. xxi, figs. 11a, b, is certainly an Edmondia ; for the 

 specimen depicted is a cast showing the groove for the shelly processes of the 

 hinge. This author mentioned this fact iu an appendix to his observations, and 

 stated that he only provisionally united the latter specimen to Allorisma. 



Fischer thought that Edmondia, de Koninck, comprised two genera, — one 

 typified by E. Josepha, which possessed no external ligament ; and another which 

 he calls Pseudedmondia, which possessed this character. De Koninck, however, 

 gives in his diagnosis the following statement : — " Sillons du ligament etroits, 

 externes," and E. Josepha does possess a very small external ligament. Fischer 

 erroneously quotes de Koninck as the authority for the presence " d'un osselet 

 calcaire (de Koninck)," but I cannot ascertain that he ever made use of such a 

 term ; indeed, de Koninck is quite silent on the subject, and does not even refer 

 to King's observations, probably because he does not appear to have examined 

 many specimens in the condition of casts. As de Koninck points out, Morris 

 placed a great many shells of widely different characters in this genus, and de 

 Ryckholt referred many species to Cardiomorpha which should be more correctly 

 placed in Edmondia. 



I am unable to discover any character of specific value to distinguish de 

 Koninck' s genus Broechia from Edmondia except that of size. Curiously enough, 

 although he compares his new genus to Cardiomorpha, and admits that they 

 possess analogous hinges, he does not contrast this genus with Edmondia further 

 than stating that he considered Morris was wrong in referring the Lutrariaprisca, 

 M'Coy, to Edmondia, because it was much less globular and less rugose on the 

 surface than the majority of species of which the genus was composed. 



De Koninck described ten species of Broechia, nine of which were supposed to 

 be new ; but most of them I believe will prove to be synonymous, the species being 

 founded on shells of different stages of growth, and on imperfect specimens. 



Sixty-eight species of Edmondia are described in the same work, twenty-six 

 being doubtfully referred to the genus ; and fifty-four are new. De Koninck 

 says of the group to which he affixes the ?, " Le second group est forme d'especes 

 ordinairement moins epaisses, plus longues que larges, dont la forme rapelle celles 

 des anciennes Venus, reunis actuellement sous le nom generique de Tapes, dont les 

 plis de la surface sont ordinairement mieux marques et plus saillants, et dont je 

 ne suis pas encore parvenu a isoler la charniere. Ce n'est dont qu'avec doute que 

 les especes de ce dernier groupe peuvent etre introduites dans le genre Edmondia." 

 Some of these species certainly should be removed from the genus, e, g. E. 

 viiui mil, E. siiblamellosa, which do not possess the simple erect hinge-line 

 posteriorly, characteristic of the genus, but which have a well-marked escutcheon. 

 These two forms are not regarded as questionable Edmondise, and I am of opinion 

 that the greater part if not all of those species referred with a ? to this genus are 



