INTRODUCTION. Panama Shells. 11 



Panama. Jamaica. 



i 



Turbinella cirstus ; T. murioata. 



Cevithium assimilatum ; C. terebellum. 



Fissnrella microtrema ; F. sp. indet. 



Area gradata ; A. Domingensis. 



Cytherea squalida ; C. maculata. 



Capsa altior ; C. Brasiliensis. 



Tellina sp. indet. ; T. bimaculata. 



The number of known species of shells which occur in 

 the Panama province, probably is not far from 1500. The 

 actual number is undoubtedly much greater. 



An examination of the catalogue of the species which we 

 collected in the Bay of Panama, will show that nearly all the 

 very minute species are new to science, although most of the 

 larger shells have been described. In other words, the 

 species which are as small as those which constitute a large 

 portion of the conchological Fauna of regions, which have 

 been thoroughly explored, have been overlooked by previous 

 collectors. This is by no means surprising, when we con- 

 sider the great number of species, and the abundance of their 

 individuals, which are of a size that is more convenient for 

 discovery and collection. It is also accounted for in part by 

 the fact that the minute species in this region are much more 

 rare in individuals. Yet the new species, which were col- 

 lected in six weeks at two localities, must be a very small 

 portion of those which actually exist in this zoological pro- 

 vince. Perhaps, therefore, the number of the undiscovered 

 species is equal to that of the known species.* 



* After describing nearly sixty new and rather small Pleurotomoid shells which 

 had been collected during the voyage of H. M. S. Sulphur, Mr. Hinds observes, 

 " when we reflect what multitudes of similar beings inhabit the recesses of the 

 globe, beyond the reach of human observation, and which at rare intervals are 

 brought to light, * * it requires the boldest stretch of the imagination even to 

 bring within the comprehension an idea of the countless multitudes of organi.-ed 

 beings of our earth, and all rich in some manner peculiarly their own, either in 

 color, sculpture, decoration, or symmetry." Hind's Zool. Voy. Kttlpli. Moll. p. 24. 



