ON MOLLUSCA OF THE WEST COAST OF NORTH AMERICA. 243 



were recorded ; this invaluable document, however, was thrown to one side 

 as useless, and has not since been found. 



The best evidence of the authenticity of the collection is in the shells them- 

 selves. These were, with very few exceptions, taken alive, and treated with 

 evident care. Every single bivalve was separately wrapped up and ticketed ; 

 the mouths of the univalves were papered to preserve the opercula; and in 

 many of the smaller species the animal was not extracted. The absence, 

 from so vast a collection, of attractive shells known to be found in neigh- 

 bouring places, such as Oliva porphyria, Terebra variegata, Malea ringens, 

 Cassis coarctata. Pectens and Pectunculi, generally seen in collections from 

 " that coast," shows that M. Reigen made little use even of the facilities of the 

 coasting trade to extend his stores. Nor are there to be seen the Pacific 

 Strombs, Cowries, Terebra?, &c, some of which even Menke allows to appear 

 in his catalogue. In one respect a town of limited trade is more favourably 

 situated for scientific purposes than a port of extensive commerce. Singa- 

 pore, the Sandwich Is., Acapulco, &c, to say nothing of places on our own 

 coast, are well known to be " hotbeds of spurious species." But among the 

 many myriads in the Liverpool collection, not a dozen individual shells were 

 found which can fairly be set down as strangers. The principal of these are — 



Arcafusca (living), which is quoted from the West Indies, and may linger in the 



Gulf Seas ; or it may have come from the East Indies on a ship bottom. 

 Conus arenatus. One very rubbed specimen ; probably from ballast. 

 Crepidula Peruviana. Two worn specimens ; probably from ballast. 

 Fissurella Barbadensis. One young fresh sp. ; probably brought over on a pebble. 



With regard to Lucina tigerrina and Mactra fragilis, of each of which one 

 fresh specimen was sent papered and ticketed with nearly related shells, we 

 have no right to deny their authenticity merely because they oppose our 

 theories ; as unexpected facts are continually making their appearance, to 

 the confusion of the mere systematizer and the corresponding delight of 

 searchers after truth. All shells of this class are included in the list, in order 

 that persons may see the bad as well as the good, and judge of its authority 

 accordingly. No attempt has been made (except with the small shells) to 

 state the number of specimens, because of the abstractions which had pre- 

 viously been made by purchasers ; but the following notes will give a tole- 

 rably correct idea of their comparative frequency, after these abstractions 

 had been deducted. 



e. r. extremely rare ; under a score. 

 v. r. very rare ; under a hundred. 



r. rare ; under two hundred. 

 n. c. not common ; or 

 n. u. not uncommon ; 



c. common ; up to 400 or 500. 



a. abundant ; 600 or 700. 

 e. c. extremely common ; 1000. 

 e. a. extremely abundant ; more than 1000. 



1 under 300. 

 List of the Reigen Collection of Mazatlan Mollusca 



No. 



Name. 



Freq. 



Other Localities. 



1 



2 



3 

 4 

 5 



6 



Class BRYOZOA. 

 Membraniporidce. 



Memhranipora denticulata, BusJc, n.s 



Gothica, Rylands, MS., n.s 



Lepralia atrofusca, Ey lands, MS., n. s 



r. 

 r. 

 r. 

 1 sp. 

 r. 

 r. 



? Persian Gulf. 

 Britain. 



Mazatlanica, Busk, n.s 



— — rostrata, Busk, n. s 



r2 



