IREDALE : OX HUMPHREY'S CONCHOLOGY. 309 



simply looked at, a different conclusion might be gained, as here all 

 the species happen to range themselves under a binominal system. 

 If any student will carefully consider all the names in tlie volume 

 no other course save that of rejection can be urged. 



Bolten, in the Mus. Bolten, 1798, apparently ignorant of Chemnitz's 

 quotations, as that volume of Chemnitz, viz. xi, is never quoted in 

 Bolteu's work, only knew Da Costa as the author of the work, as 

 references to that name appear on pp. 1, 2, 3, 4, 5, 6, 7, where Latin 

 names are given to the species figured in the " Conchology ". 

 Maton & Rackett, in their Historical Account of Testaceological 

 Writers (Trans. Linn. Soc, vol. vii, 1804), wrote under the name 

 Da Costa — " Still more acceptable to the public were two other 

 works of this author; one of which, however, was on too extensive 

 a scale to admit of being completed ; we mean the ' Conchology or 

 Natural Histori/ of Shells\ which was published, anonymously, in 

 folio numbers, but never proceeded beyond twenty-six pages of letter- 

 press and twelve plates." 



Doubt as to the authorship of the work appears to have arisen later, 

 as Dillwyn in his Descr. Cat. Recent Shells, vol. i, p. ix, 1817, gave 

 a "Catalogue of the Books consulted", and on p. ix wrote: 

 '' Humphrey'' s Couch. Conchology, or Natural History of Shells. 

 (Supposed to be the joint work of E. M. Da Costa and George 

 Humphreys)." In the Index Hist. Conch., Lister published in 1823, 

 Dillwyn simply wrote: "Humphreys and Da Costa. Conchology, or 

 Natural History of Shells." 



It may be of interest to note Da Costa's own account. In the 

 Elements of Conchology, 1776, p. 51, he wrote : " A new anonymous 

 Conchology began to be published in this Metropolis in 1770, in 

 folio, illustrated with copper ])lates. It was to be published in 

 monthly numbers, and each number to contain two plates of Shells, 

 with their descriptions in English and French. It was also intended 

 to be a General Natural History of Shells, and to include the figures 

 of all the known species, common as well as rare, beautiful, or other- 

 wise ; and some copies were designed to be accurately coloured for 

 the use of the curious. Si.x numbers of it were published, compre- 

 hending the families of the Limpets, Sea-Ears, and Worms; but not 

 meeting with suitable encouragement, the authors have laid it aside, 

 at least for the present." Later, when reproducing figui'es, Da Costa 

 wrote, "taken from the anonymous new Conchology." 



While strongly of the opinion that Da Costa was the author of the 

 work, this note has been written for the purpose of emphasizing the 

 fact that quotations to "Da Costa ", " Da Costa Conch. ", or "Humph. 

 Conch." all refer to the same work. This work was published 

 anonymously, the author being given as " A Collector ", and under 

 this heading the book may be met with in some library catalogues. 



