VI 



In the year 177", Dyv Costa brought out his Hiflo- 

 jia Naturalis Teflaceorum Britannias, or Britifli Concho- 

 logy, with copious defcriptions, embellifhcd with 123 fi- 

 gures of diil;in6l fpecies, many of which were unknown 

 10 preceding writers. This author has profefTedly en- 

 tered upon a new fyftem, built upon his Elements of 

 Conchology, before publiflied ; and it is to be lamented, 

 that he did not at lea ft adopt the Linnsean fpecific, or 

 trivial names, to which the ear of the conchologifl has 

 been fo long familiarized : his fynonyms, however, are 

 copious, which facilitates the identity of each fpecies. 



At this time, no one had thought the more minute 

 fiiclls of our coafts, of fufficient importance to give them 

 a thorough inveftigation, or at leaft to defcribe them, 

 although fomething of this nature had been attempted 

 at Rome by Plancus in 1760, entitled Liber de Conchis 

 minus Notis, in Littore Ariminenfi. 



To the indefatisjable refearches of Mr. Boys of 

 Sandwich, this taflc was referved, by whofe ample aflift- 

 ance Mr. Walker was made acquainted with all the mi- 

 crofcopic fliells of that coaft, which enabled him in the 

 year 1784 to publifli a work, entitled Tellacea minuta 

 rariora ; in which are defcribcd 87 minute fpecies, ac- 

 companied with figures, the raoft part of which were 

 entirely new. This undertaking laid open an entire new 



field 



