300 BULLETIN OF THE 



have given the greatest depth of living young, as the dead tests may 

 have been dropped by fishes or carried by currents. The character of 

 the Echinian fauna, on the three belts developed by the soundings of Mr. 

 Pourtales, are tolerably well defined; the first zone being littoral, and 

 extending to 90 fathoms, is characterized by species, the majority of 

 which do not range beyond 40 fathoms, with a few species ranging 

 somewhat beyond, to about 120 fathoms. 



The second zone (from 90 to 250 fathoms) is characterized by 

 species extending into the first somewhat and attaining a range of about 

 270 fathoms, with an admixture of a few species extending from 140 to 

 310 fathoms. 



The third zone contains the typical deep-sea species of Florida, 

 extending from 315 to 500 fathoms. 



Although we have not a sufficient number of soundings to establish 

 homogeneous zones of geographical and bathymetrical range, an 

 analysis of the above grouping of species shows us something analo- 

 gous to the distribution of animal and vegetable life in latitude and 

 height ; the oceanic distribution 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, Moera 

 atropos, Echinocardium Kurtzii, and as far as the southern part of 

 Cape Cod Echinocidaris punctulata, species which in Florida have a 

 range in depth to 125 fathoms. Of their range further north we know 

 nothing. 



The following North-European species — Cidaris papillata, Schizas- 

 ter fragilis, Echinus Flemingii, Echinocardium ovatum, E. cordatum, 

 Echinocyamus ? pusillus, Brissopsis lyrifera — are represented by their 

 allies or by the identical species: viz. Dorocidaris abyssicola, Schizaster 

 cubensis, Echinus gracilis, E. Flemingii, Echinocardium ovatum, E. 

 Kurtzii, Stolonoclypus prostratus, Brissopsis lyrifera, which have 

 a range somewhat more extensive than the previous species. These 

 same species, with the addition of Brissus columbaris, Echinocardium 

 la-vigaster, Diadema antillarum, and Echinocidaris punctulata, are again 

 the representatives of a Mediterranean fauna strikingly similar, consist- 

 ing of Cidaris hystrix, Schizaster canaliferus, Echinus nielo, Echinocar- 

 dium cordatum, Echinocyamus ? pusillus, Brissopsis pulvinata, Brissus 

 Scillae, Echinocardium gibbosum, Diadema europaeum, Echinocidaris 



