MUSEUM OF COMPARATIVE ZOOLOGY. 2Jh 



At a depth of 30 to 40 fathoms commences a third set of specie-, the 

 majority ranging to about 160 fathoms, though two species range to 

 270 fathoms, marked *, and a few species commence at a greater depth, 

 SO to 90 fathoms. These species are 



* Dorocidaris abyssicola. 

 Echinus gracilis. 

 Genocidaris maculata. 



* Trigonocidaris albida. 

 Rhyncholampas caribbsearum. 

 Echinolampas caratomoides. 

 Neolampas rostellatus. 

 Brissopsis lyrifera. 

 Agassizia excentrica. 

 Echinocardium ovatum. 



" lrevigaster. 



" Kurtzii. 



Schizaster cubensis. 

 At a depth of about 140 fathoms, extending to over 310 fathoms, are 

 found most interesting species : 

 Caenopedina cubensis. 

 Podocidaris sculpta. 

 Echinus Flemingii. 



While near the lowest depth reached by the above species we strike 

 upon a peculiar fauna recalling types of the cretaceous period, extend- 

 ing from 315 fathoms to the greatest depth attained in the straits be- 

 tween Florida and Cuba. These are 



Salenocidaris varispina. 



Pourtalesia miranda. 



Lissonotus fragilis. 



Two species — Stolonoelypus prostratus and Mellita hexapora — have 

 t!ie greatest bathymetrical range, extending from the shore, the one to 

 270 fathoms and the other to 325 fathoms. I would state, however, that 

 it is only the young which have this great range; the adult specimens are 

 limited to a quite shallow- zone. — about 40 fathoms. In the young of 

 our common northern Cuvieria the reverse takes place, the young being 

 quite common at low-water-mark, while young Echinarachnius and 

 T. drobachiensis are found at a much greater depth than the adult. 1 

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