STILL FOUND IN A LIVING STATE. 347 
such as had already been termed ovaries or egg-sacs in the allied 
species, were separated by these lines as by septa. Now, since 
this form constituted chain-like animal stocks, the central aper- 
ture of the individual bars, both in them and in the fossil bodies 
resembling them externally and internally, could not be the 
mouth aperture present in the Navicule ; but it was evident that 
the fossil single bars had been produced from broken chains, 
which originally, like the living ones, had formed zigzag bands, 
a circumstance which had already been observed in the Euro- 
pean Tabellaria vulgaris*, which, however, does not show any 
interior division into chambers. Thus, then, the absence of 
inner chambers became an important character of distinction 
of these forms from the Tudellaria; and the chain and zigzag 
band formation, brought about by imperfect self-division, to- 
gether with the consequent different position of the alimentary 
apertures, became likewise important characters for distinguish- 
ing them from the Navicule. This new generic type was cha- 
racterized with the name of Grammatophora, and arranged near 
to Baciilaria and Tabellaria. 
The species from Peru, Grammatophora oceanica, was, it is 
true, not found to be identical with the fossil Grammatophora 
(Navicula) africana; but recently Gr. oceanica has been found 
alive in the North Sea, as well as fossil in the chalk marl of 
Oran; and even the true fossil Gr. africana of the chalk marl 
has been found in a living state in the Cattegat. 
There was found also on some Mexican Alge, which Carl 
Ehrenberg had recently brought from Vera Cruz, a specimen 
of Coscinodiscus eccentricus, which had already been indicated 
as living in the North Sea, near Cuxhaven, and the fossil shells 
of which lie imbedded in the chalk marl of Oran in Africa. 
There were, moreover, on these Mexican Algz, two distinct 
Species of the new genus Grammatophora, which I have called 
Gr. mexicana and Gr. undulatat. 
* In my work, Ueber die Infusionsthierchen, 1838, p. 199. 
+ In the communication made on the 27th of July, 1840, it was pointed out 
that the examination of marine forms from Peru and Mexico had led to the 
result, not unexpected, indeed, but hitherto uncertain, that there really are 
peculiar genera of Infusoria in other parts of the earth, while those previously 
enumerated have been likewise found in Europe, with the exception of a few 
“a less accurately examined. Podosira moniliformis, a petiolated Gallionella 
rom Callao, was represented as a very decidedly peculiar form, and the genus 
Grammatophora, comprising three species, was then also only known from 
America and the chalk marls of Africa. But since then this latter genus has 
been detected in numbers in the North Sea and Baltic; and thus, then, Podo- 
2a? 
