• 1V INTRODUCTION. 



Survey Expeditions, so that the list of species has been more than doubled 

 by the dredgings made since 187G. 



In consequence of the great delay in preparing the illustrations of the 

 more minute structure of the Salenidse, the Echinothuriae, and many of the 

 less well known Spatangoids, the concluding Part of this Report will appear 

 on their completion. 



The details of the geographical distribution of the Echini of the '-Blake " 

 having already been given in the Preliminary Reports (Bull. M. C.Z., Vol. V. 

 No. 9 1878, Vol. VIII. No. 2, 1880). to avoid repetitions 1 merely refer to 

 the previously published records, as well as to the list of the dredging sta- 

 tions occupied by the -Blake" (Bull. M. C. Z., Vol. VI. No. 1, 1870.. Vol. 

 VIII. No. 4, 1881). These give the position, the depth, the temperature, and 

 the character of the bottom. On the completion of the Be] orts by the differ- 

 ent specialists, who have kindly consented to work up the collections of the 

 "Blake." including the examination of the bottom samples. I hope to make 

 a revision of the geographical and bathymetrical distribution of the various 

 groups, so as to give a good picture of the animals associated at the prin- 

 cipal localities which make up the-Fauna characteristic of certain well-defined 

 regions. Nothing can he more different, for instance, than the animals 

 found associated on the rocky bottom along the southern slope (in deep 

 water) of the Florida Beef, on the Pourtales Plateau, with its predominance 

 of Corals. Rhizocrini, and Starfishes, from those found in the calcareous 

 ooze of the trough of the Gulf Stream (Lamellibranchiates, Holothurians. 

 &C.); and again from the association of the masses of GorgoniaB, SalenisB, 

 and Terebratulae, oil' the north coast of Cuba, brought up in a single haul of 

 the trawl. Nor can there be a greater contrast, between the inhabitants 

 of the Pteropod ooze in deep water oil' the west end ol Santa Cruz, with 

 its preponderance of Phonnosomae, of Asthenosomaa, ami Hyalonemse, and 

 those of the forests of Pentacrini and Gorgonise, ami the accompanying 



Comatulse ami Ophiurans, living in such abundance on the windward coast 

 of St. Vincent. 



We may contrast, again, the deep-water fauna off the Tortugas, in the 

 coral ooze, mainly made up of a most remarkable association of Fishes 



