CALlFORNIAls PROVINCE. 375 



Lutrai'ia Nuttalli. Cyathodonta undulata. Machaera maxima. 



Platyodou caucellatus. Sphenia califoruica. Mya praecisa. 



AmphichaenaKindermanni. Periploma argentaria. Panopaea generosa. 



Lyonsia, 1. Thracia, 1. Solecurtus subteres. Pholas Califoruica. 

 Pandora, 1. Saxicava, 2. Machaera lucida. „ concamerata. 



XIII. Panamic Pbovince. 



The Western coast of America, from the Gulf of California to Payta in 

 Peru, forms one of the largest and most distinct provinces. The shells o^ 

 Mazatlan and the Gulf have been imperfectly catalogued by Menke and are 

 now under examination by Mr. P. Carpenter, who states that they amount to 

 about 500 species, of which perhaps half are common to Panama and Peru ; 

 a very few are common to the west coast of the Promontory and very few 

 (including Purpura patula and Mactra simills) to the West Indies ; still 

 fewer to the Pacific coasts and islands, and one or two identical or closely 

 analogous with Senegambian and British species, (e. g. Kellia sahorlicularis.) 



The late Prof. C. B.Adams of Amherst published, in 1852, a very valuable 

 work on the shells of Panama, in which the total number of species found in 

 the province is estimated at 1500, of which ''perhaps none exist beyond — 

 all of the few examples which are supposed to have a wider range, are more or 

 less doubtful." He remarks that " in general there is a great dissimilarity 

 between the shells of this and the Caribbean Province" in which he had him- 

 self collected extensively ; the number of large species was much greater in 

 Panama.* 



The river-openings of this coast are bordered by mangroves, amongst 

 which are found Potamides, Areas, Cyrenas, Potamomyas, Auriculas and 

 Purpuras, whilst lAtorince climb the trees and are found upon their leaves. 

 The ordinary tide at Panama amounts to 16 or 20 feet, the extreme to 28 

 feet, so that once a fortnight a lower zone of beach may be examined and 

 other shells collected ; the beach is of fine sand, Avith reefs of rocks in the bay. 



Gallapagos Islands. — Out of 90 sea-shells collected here by Mr. Cuming 

 47 are unknown elsewhere ; 25 inhabit Western America, and of these 8 are 

 distinguishable as varieties; the remaining 18 (including one variety) were 

 found by Mr. Cuming in the Low Archipelago, and some of them also at the 

 Philippines. {Darwin, p. 391.) 



Litoral shells common to Panama and the Gallapagos (C. B. Adams.) 



Cyprsea rubescens Columbella atramentaria. Eiciuula reeviana. 



Mitra tristis. „ bicanalifera. Cassis coarctata. 



Planaxis pianicostatus. „ haemastoma. Oniscia tuberculosa, 



Purpura carolinensis. Columbella nigricans. Conus brunneus. 



* Mr. Adams found but one shell common to the two sides of the Isthmus— 

 Crepidula unguiformis—v/ich is said to be found throughout the warmer latitudes, 

 but is really an abnormal form of many distinct species of Crepidula, caused by 

 growing in the interior of other shells. 



