ANIMAL NATURE OF DIATOMEiE. 445 



Schizonema albicans, Kiitz., (Micromega.) 



If the specimens from Dalmatia, which I think ought 

 to be referred to it, really belong to this species, the 

 name is not well chosen ; indeed it indicates a condition 

 which the author confesses not to be constant, {vel 

 olivaceo-virescens) and which is common to many species 

 in a state of decay. Length of Naviculse 0'036, (Kiitzing 

 says ith of a line = 0-03 millim., and figures them 

 6 milhm. = 0"0142), the breadth of the primary surfaces 

 O'OOGl, of the secondary, which are broadly elliptical, 

 it is a millimiUimetre more. 



Schizonema torquatmn, Harv. 

 (Micromega polyclados, Kiitz.) 



It is on Kiitzing's authority that I refer to his species 

 the authentic specimen which I received from Berkeley 

 with the name above mentioned. In this I find the 

 length of the Naviculse 0-03 millim., and the breadth 0-005 

 in the lateral surfaces, which exceed the primary by a 

 millimilHmetre. The dimensions, therefore, (not described 

 by Kiitzing,) are something less than twice those of his 

 figure. Kiitzing is right in remarking that my Schizonema 

 nebulosuni, which I erroneously considered belonging to 

 the genus Frustulia, corresponds to this species in the 

 form and dimensions of the Naviculae. Although when 

 dried upon paper it only forms a light cloud, yet, when 

 diligently examined, it proves similar in ramification to 

 Harvey's species. 



Schizonema pallidum, Ag., (Micromega.) 



In a specimen gathered by me at Trieste, and corres- 

 ponding perfectly with the description and figures, I find 

 the greatest length of the Naviculse to be 0-04, whilst 

 Kiitzing says it is ^th of a line =- 0-049 millim. The 



