304 REPORT ON THE STATE CABINET. 



upon the other valve ; but it is not imperforate in fact. If it be any 

 satisfaction to Mr. Billings to know the fact, I may mention that a 

 critical examination of the internal spires of this species has shown it to 

 be somewhat different from the similar appendages of typical forms of 

 Meristella ; but whether they may correspond with the spires in the 

 " tijpical figure" of Athyris cited by him, I am not prepared to say, nor 

 can I assert that they correspond with the similar appendages in M. tumida. 

 Of the other species, A. maia^ I have had in my collection for many years 

 specimens from the locality in Canada cited by Mr. Billings, and also 

 from Ohio ; but I have always regarded it as a true Spirifer, and until it 

 shall be proved destitute of area,* and with internal appendages corre- 

 sponding to Athyris, I shall prefer to know it as a Spirifer. Even 

 admitting all that Mr. Billings has claimed in regard to Athyris, it does 

 not appear that he is prepared to give us much information in regard to 

 the extent and limits of the genus about which he has written so much. 



Note. — Since it appears that zoological nomenclature and argument, 

 and not structural characters, are to be relied upon for the establishment 

 of the points in dispute ; therefore, in order that the student of Palgeon- 

 tology may have the benefit of Mr. Davidson's opinions upon the question 

 of nomenclature, regarding Athyris and Spirigera, I have translated 

 from the French edition of his Introduction to the Study of Brachiopoda, 

 1856, the following observations. It is easy to understand how certain 

 authors, following the views of Mr. Davidson, published in 1853, should 

 have adopted the names of Athyris and Spirigera: 



" In 1853, I was very much perplexed in regard to the name Athyris, pro- 

 posed by Prof. M'CoY for certain species, which ill accorded either with the 

 etymology of that name or with the diagnosis given briefly, and without detail 

 at the outset ; that is to say, nearly orbicular, small ; without area or cardinal 

 line.; spiral appendages very large, occupying the greater portion of the interior 

 of the shell. The author cites some examples, among which are shells evidently 

 perforate, such as the T. concentrica, De Buch, and others which do not appear 

 to be so ; and, furthermore, some belonging to the Genus Spirifera of Sow- 

 ERBY. It is true that the Professor alleged, in support of his theory, that his 

 type, cited above, was, when in a state of perfect preservation, imperforate, 

 and that he had given to this section a name expressive of a real characteristic. 

 In 1859, M. D'Oebigny opposed the appellation given by M'Coy, on the ground 

 that it was in complete contradiction to the zoological characteristics.! He 



* I might remark that although described as without area, the artist has taken the liberty of 

 indicating something of the kind in the figure of the specimen. 

 ■\ PaKontologie Frani^aise ; Terrains Cntaces, Vol. iv, p. 357, 1847. 



