NOTES AND CORRESPONDENCE. 



Eulenstein's Series of Diatomacese — In the ' JournaP for 

 January, 1867 (p. 64), we took occasion to call attention to 

 a prospectus which had been issued by M. Eulenstein of 

 Canstadt, respecting two Series of Collections of Diatomaceae 

 which he was proposing to issue, each in five Parts, containing 

 100 species. Owing partly to illness, and partly to the large 

 number of subscribers, the issue of these collections has been 

 somewhat delayed, but we have now before us the First 

 Century of the second or "Standard^' series, which contains 

 the following species, amongst which those marked with an 

 asterisk are from original specimens or gatherings. The 

 specimens appear to be in an admirable condition, and to be 

 well mounted, and the present issue shows that M. Eulenstein's 

 laborious and most useful design will, doubtless, be carried out 

 in the manner to be expected from his well-known reputation. 

 We are sorry to find that, in consequence of the undertaking, 

 on the original terms, proving more expensive than was antici- 

 pated, a reissue of the series could only take place at a some- 

 what advanced charge, which, however, would then leave the 

 collection very cheap. 



The specimens in the present collection are, with few 

 exceptions, quite unmixed, and remarkably clean. In most 

 cases both entire frustules and separate valves are given, and 

 in some the entire organism is preserved in a fresh state in 

 one slide, and the cleaned valves in another. Many of the 

 species, as will be seen, are of considerable rarity. 



List of the species of Diatomacese contained in the First 

 Century of 'Eulenstein's Typical Series' : 



Achnantbes longipes *HemiauIus polycystinorum 



„ brevipes * ,, alatus ? 



*Achnautbidium lanceolatum Homoeocladia inartiana 



* „ liueare *Hyalosira obtusangula 



Ampliipleura pellucida Islhniia enervis 



Amphiprora paludosa Liciiiophora flabellata 



„ Pokornyaua Mastogloia lanceolata 



Ampiiitetras antediluvian a * „ elegans 



