EXTRACTS 



From the Preface to the Descriptive Catalogue of the British 



Mnsenm. 



The Collection, from which the shells described in the following 

 pages have been carefully selected, was made at Mazatlan (/a^.23** 

 N., long. 107° W.), during the years 1848 - 50, by a Belgian gen- 

 tleman named Frederick Reigen. The bulk of it was sent to Liver- 

 pool for sale in 1851, and circumstances enabled me to make a 

 searching examination of it. Dr. Gray having requee^ted that the 

 (comparatively) small selection which I had made for my own use 

 should be deposited in the British Museum, I judged it conducive 

 to the interests of science to obtain possession of the whole of the 

 then-remaining stock, which was about to be dispersed; and to 

 select as many specimens as might be required (1) to illustrate the 

 local fauna of a known station at the mouth of the Gulf of Cali- 

 fornia; and (2) to exhibit the amount of variation, whether great 

 or little, observed in comparing together large numbers of indivi- 

 duals in the various species. The latter object appeared of no slight 

 importance, especially for the sake of inland naturalists; who have 

 usually to depend on the very limited number of specimens which 

 are to be seen in public, still more so in private collections. 



The series of shells here enumerated* is presented to the Trustees 

 of the British Museum, and accepted by them, on the following 

 conditions : (1) That it he preserved separate and intact j as a local 

 collection; (2) That it he always open to the use of students, subject 

 to the usual conditions; (3) That the donor be allowed to arrange 

 the collection in its permanent place of abode; and (4) That a 

 Descriptive Catalogue of it be printed under the direction of the 

 Trustees. 



The collection consists of about 8873 specimens (2505 Bivalves, 



* The series presented to the New-York State Cabinet is an exact duplicate of that presented 

 to the British Museum, and has been accepted on the same conditions, except the printing of the 

 Descriptive Catalogue. 



