382 On Infusoria in Dust-showers and Blood:rain. 
9. AMERICA. 
1. S. America—P.C. 16385? 1680 1737 1799 1802 18192. 
2. WN. America —P.C. 1741 1780 1785 1814 1848 1848, 
10. AusTrRALra. 
P.C. 1841? 
The volume closes with a series of conclusions from the facts 
mentioned. Ehrenberg remarks that these showers appear to 
prevail most within a zone extending from the part of the Atlan- 
tic off the west coast of Middle and North Africa, along in the — 
direction of the Mediterranean —~ reaching a short distance north 
this sea, and continued into Asia between the Caspian sea and 
the Persian Gulf, perhaps to Turkistan, Kaschgar and China; and 
they seldom reach north to Sweden and Russia. This zone accord- 
ing to the observations of Tuckey, has a breadth of 180 miles 
in the North Torrid zone. The reddish color of the dust as well 
as the organic forms, show that the dust is not of African pee. 
Moreover the petra a and sirocco are found to afford the sam 
species of organisms. 
Ehrenberg re peath again his opinion that these phenomena are at 
not to be traced to mineral material from the earth’s surface, nor | 
to revolving masses of dust material in space, nor to pee 
currents simply : but to some general law connected with t 
earth’s atmosphere according to bss there is a celbaleveléh- 
ment within it of living organism 
The whole number of species of organisms observed is 320. 
Of marine genera there are only the following: Coscinodiscus, — 
Diploneis, Goniothecium, Grammatophora, and Biddulphia, be-— 
sides some Polythalamia and Spongolites. ‘The following are 
American forms: 
Arcella constricta. Eunotia quaternaria. Navicula undosa, 
Desmogonium Guayanense. quinaria. Stauroneis dilatata. 
Eunotia Camelus Gomphonema Vibrio. s a Peru 
. saan Himantidium Soe? Synedra Entom 
“o°  Plews. Zygodon. Fragmenta tence 4 
A simultaneous occurrence of dust-showers and falls of mete- 
oric stones, has been observed in probably eighteen instances 
before the Christian era. During the Christian + era, Rathod co- 
incidences have been observed, making thirty-two in 
_ We insert here from this most remarkable work of earth 
the following tables, which present to the eye the range of show- 
ers through which the different species of organisms have been : 
ed.* 
The numbers in the table; following = names of the species, refer to | 
s of or oar on the plate, 
of the columns, where there se pet for the same shower, have 
These omitted col he 
