JUKES-BEOWNE : ON POLl's GENERIC NAMES. 101 



provides by compounding the Greek word derma with the name of 

 each genus. Thus, from the Callista-^vom^ of animals we have the 

 generic name Callistoderma for the shells, which form the coverings of 

 the various species of Callista. 



In thus attempting to develop a nomenclature for the animals as 

 well as for the shells he was really only following in the footsteps 

 of Linnaeus, who also used a separate terminology for the animals 

 of different kinds of Mollusca, but apparently he saw so little 

 difference in them that he was content to give a single name, such 

 as Tethys^ Limax, or Ascidia, to a whole order or division of Molluscous 

 animals. Poll, on the other hand, saw that the animals of each order 

 did present differences which might be regarded as generic, though 

 the genera so distinguished might not always correspond or coincide 

 with the genera established on the shells. 



In this connection it is worthy of note that Poll's idea was 

 thoroughly understood by a writer who may have been his con- 

 temporary, and who published an essay on the classification of shells 

 only sixteen years after the date of Poll's second volume. This was 

 J. K. Megerle (von Miihlfeld), whose " Outline of a new System of 

 Conchology" was published in 1811.' He defines his genera by the 

 characters of the shell and its hinge, and at the end of each description 

 he briefly states that the animal is a " so-and-so," using a combination 

 of Linne's and Poll's names for the molluscs. Thus under his genus 

 Tapes he says "the animal is a Callista"; similarly of Mactra he 

 says the animal is a Callista, but of Pisum he says the animal is 

 a " Thelysr 



Lamarck, on the other hand, though also a contemporary, seems to 

 have been entirely ignorant of Poll's magnificent work. 



Swainson, however, in his Treatise on Malacology (1840) shows 

 that he was fully aware of the fact that the generic names proposed 

 by Poll were only applicable to the animals, for on p. 16 he remarks : 

 " In estimating the merits of these three great men — Poll, Cuvier, and 

 Lamarck — in regard to their arrangement of the testaceous Mollusca, 

 it may be stated that the first confined his system entirely to the 

 animal, giving to it a different name to that of the shell, so that if the 

 animals of two conchological genera {a.?, Aviciila and Lima) were nearly 

 alike, they were placed in his system in one and the same genus." 



So far as I can ascertain. Leach (in 1852) ^ was the first to introduce 

 some of Poll's generic names into our conchological nomenclature, 

 under the erroneous impression that they were applicable to shells. 

 In the following year (1853) Morch^ used several of Poll's names 

 in the same manner, and although this publication was merely a sale- 

 catalogue the names used and proposed by him have always been 

 regarded as properly published. A few years later the brothers 

 H. and A. Adams, in their " Genera of Kecent Shells," the latter 

 portion of which was issued in 1856-8, adopted most of Morch's 



1 Del- Gssellsch. Naturforsch. Freuude, Berlin Magasin (1811), p. 38. 



- " Synopsis of the Mollusca of Great Britain," edited by J. E. Gray, 1852. 



^ Cat. Couch. Comes de Yoldi, part ii, Hafuia\ 1853. 



