BATHYMETRICAL AND GEOGRAPHICAL DISTRIBUTION. 371 



being of course an identity for northern latitudes and southern depth, or a 

 representation by species closely allied. 



For instance, we find littoral, as far north as North Carolina, Moira 

 atropos and Echinocardium cordatum; Arbacia punctulata, as far north as 

 the southern part of Cape Cod, species which in Florida have a range in 

 depth to 125 fathoms. Of their bathymetrical range farther north we 

 know nothing. 



The following North European species, Dorocidaris papillata, Schizaster 

 fragilis, Echinus norvegicus, Echinocardium flavescens, E. cordatum, Echino- 

 eyamus pusillus, Brissopsis lyrifera, Asthenosoma hystrix, are found in 

 Florida. These same species, with the addition of Brissus unicolor, Echino- 

 cardium pennatificlum, Diadema setosum, and Arbacia punctulata, are again 

 the representatives of a Mediterranean fauna strikingly similar, consisting 

 of Schizaster canaliferus, Echinus melo, Echinocardium mediterraneum, 

 Centrostephanus longispinus, Arbacia pustulosa. The specific representation 

 on both sides of the Isthmus of Panama is becoming every day, as far as 

 Echinoderms are concerned, more strikingly identical. Since the list given 

 by Mr. Verrill, several species have come to light, and the following com- 

 parative list (p. 372) of species on both sides of the Isthmus, extending 

 from Peru to the Gulf of California on the Pacific, and including on the 

 eastern side the Gulf of Mexico, Florida, the northern coast of South 

 America, the West Indies, and the Bahamas, may not be out of place. (I 

 have examined all the species there named.) As this list will undoubtedly 

 be greatly increased by additional dredging from the Hassler Expedition, 

 it is given as published in the Preliminary Report, and no attempt has been 

 made to re-examine the question of the specific identity of any of the 

 Echini on the Atlantic and Pacific sides of the Isthmus of Panama. 



With the exception of three Panama species, all the West Coast species 

 have representatives on the Eastern Coast. The Eastern species which have 

 not as yet been found represented on the West Coast are the deep-water 

 species of Mr. Pourtales's collection, and, what is very peculiar, three species, 

 Echinoneus semilunaris, Echinocardium cordatum, and Echinolampas, belong- 

 ing to genera which have a most extensive range. 



The relation of the Caribbean fauna to the existing geographical distri- 

 bution of Echini is shown by the accompanying faunal table, page 373, and 

 the maps of Part I. Plates A-G. 



