THE BASIN AND BED OF THE ATLANTIC. 331 



from the bottom of "blue water" in the narrow Coral Sea, the 

 broad Pacific, and the long Atlantic, and they all tell the same 

 story, namely, that the bed of the ocean is a vast cemetery. The 



"3cl. All these specimens are very rich in the silicious shells of the Diatomacea?, 

 which are in an admirable state of preservation, frequently with the valves united, 

 and even retaining the remains of the soft parts. 



"4th. Among the Diatomes the most conspicuous forms are the large and beauti- 

 ful discs of several species of coscinodiscus. There is also, besides many others, a 

 large number of a new species of rhizosolenia, a new syndendrium, a curious spe- 

 cies of cheetoceros, with furcate horns, and a beautiful species of asteromphalus, 

 ^\ hich I propose to call Asteromphalus Brookei, in honor of Lieutenant Brooke, to 

 whose ingenious device for obtaining deep soundings, and to whose industry and zeal 

 in using it, we are indebted for these and many other treasures of the deep. 



' ' 5th. The specimens contain a considerable number of silicious spicules of sponges, 

 and of the beautiful silicious shells of the polycistinea. Among the latter I have 

 noticed Cornutella clathrata of Ehrenberg, a form occumng frequently in the At- 

 lantic soundings. I have also noticed in all these soundings, and shall hereafter de- 

 scribe and figure, several species of eucyrtidium, halicalyptra, a perichlamidium, a 

 stylodictya, and many others. 



"6.-1. I have not been able to detect even a fragment of any of the calcareous 

 shells of the polythalamia. This is remarkable, from the striking contrast it pre- 

 sents to the deep soundings of the Atlantic, which are chiefly made up of these cal- 

 careous forms. This difference can not be due to temperature, as it is well known 

 that polythalamia are abundant in the Arctic Seas. 



"7th. These deposits of microscopic organisms, in their richness, extent, and the 

 high latitudes at which they occur, resemble those of the antarctic regions, whose 

 existence has been proved by Ehrenberg, and the occurrence in these northern 

 soundings of species of asteromphalus and chtetoceros is another striking point of 

 resemblance. These genera, however, are not exclusively polar forms, but, as I have 

 recently determined, occur also in the Gulf of Mexico and along the Gulf Stream. 



" 8th. The perfect condition of the organisms in these soundings, and the fact 

 that some of them retain their soft portions, indicate that they were very recently in 

 a living condition, but it does not follow that they were living when collected at such 

 immense depths. As among them are forms which are known to live along the 

 shores as parasites upon the algee, etc., it is certain that a portion, at least, have 

 been carried by oceanic currents, by drift ice, by animals which have fed upon them, 

 or by other agents, to their present position. -It is hence probable that all were re- 

 moved from shallower waters, in which they once lived. These forms are so minute, 

 and would float so far when buoyed up by the gases evolved during decomposition, 

 that there would be nothing surprising in finding them in any part of the ocean, 

 even if they were not transported, as it is certain they often are, by the agents above 

 referred to. 



"9th. In conclusion, it is to be hoped that the example set by Lieutenant Brooke 

 will be followed by others, and that, in all attempts to make deep soundings, the ef- 

 fort to bring up a portion of the bottom will be made. The soundings from any part 

 of the ocean are sure to yield something of interest to microscoi)ic analysis, and it is 

 as yet impossible to tell what important results may yet flow from their study. 



