;S^. S. Buchnan — The Genotype of Spirifer. 1 9 



true the first species rule is itself an absurdity. It is just a con- 

 trivance to save a compiler's time, relieving him of the necessity 

 or reading an original diagnosis to find out an author's meaning. 

 When the first species has obtained its position, not for a zoological 

 reason, but for an alphabetical, a geological, or a typographical 

 reason, its selection as genotype may result in an absurdity — it 

 may fail to fill the author's diagnosis. 



It may be urged that Sp. cuspidatus is the monotype of Spirifer. 

 That I challenge. I would argue that the description of S. cuspi- 

 datus is a separate act, not a part of Sowerby's generic diagnosis. 

 That is complete in itself. Supposing that the description of S. cuspi- 

 datus had been written by another author, then S. cuspidatus 

 would not be the genotype of Spirifer. Why should it be so because 

 the description was written by Sowerby ? 



The diagnosis of Spirifer {Min. Conch., ii, Feb., 1816, p. 41) 

 says, " The shells of this genus " ; that is plural, that rules out 

 a monotype ; the genus is founded on several species which are 

 genosyntypes. This is shown further : "I think this genus will 

 comprehend nearly all the shells retained as Terebratula by Lamarck 

 which have a triangular foramen . . . The several individuals 

 in which I have discovered spiral appendages (he mentions Derby- 

 shire, Irish, and Van Diemen's Land specimens) bear a considerable 

 natural afiinity to each other, from which circumstance we may 

 venture to place many analogous species in this genus, although 

 their interior has not been fully exposed." That is what he has 

 done with S. cuspidatus ; he has placed it in Spirifer on sufferance ; 

 as an analogous species, for he expressly says (p. 43), " I have not 

 discovered the spiral appendages [of S. cuspidatus^ That excludes 

 it effectually as the genotype. He placed it in Spirifer by intuition; 

 it had the triangular foramen. It was a case of typographical 

 necessity. His material of Spirifer with the spirals discovered was 

 held up by the Linnean Society ; but the plate of S. cuspidatus was 

 ready. It could not be placed in Terebratula ; it was Spirifer by 

 presumption if not by proof. Anyone who has had to draw up lists 

 of species and assign them to new genera will have been confronted 

 with the same difficulty and have committed a similar act. 



In choosing a lectotype of Spirifer out of these species of Derby- 

 shire, etc., shells, consideration should be given to Sowerby's 

 further writings. First is his description of S. cuspidatus, saying, 

 " Spiral appendages . . . may be seen in Anomia trigonalis of Martin." 

 That is the first species mentioned. Then in 1818 was published 

 Sowerby's paper in the Linnean Transactions, vol. xii, wherein he 

 figures Terebratula striata showing spirals. But in his description 

 of S. trigonalis (M.C. ii, pi. cclxiii, p. 117) he admits that he had 

 " confounded it with Anomia striata of Martin ... in the Linnean 

 Transactions ". Evidently he had discovered this mistake after 

 the reading of his paper to the Linnean (December, 1814) and before 

 the publication of his description of S. cuspidatus (February, 1816), 



