3 2 



PSEUDO-SYNEDRA. 



HI 



Pseudo-Synedra Leud-Fortm. (Diat. Maiaisie, 



P- 32). 



Without any generic diagnosis being given by the author, 

 Mr. Leuduger-Fortmorel includes in his genus two very different 

 forms. 



The PS. Peragalli (fig. 74), " oar-shaped," with fine parallel 

 stride (12 in 1 c.d.m.) and without pseudo-raphe; and the other, 



The PS. Debvi, in the form of a " constricted dagger," and 

 furnished with a narrow pseudo-raphe, very distinct, and having 

 likewise parallel strise (10*5 in 1 c.d.m.). 



The habitat of the first is Java, and the second Sumatra. We 

 are not acquainted with either form beyond the figures. 



Fig. 76. 



Pseudo- 



synedra 



Peragalli. 



GENUS 42. 



-ASTERIONELLA HASSALL, 1850. 



Valves narrow, linear, 

 with apices unequally 

 capitate ; girdle face 

 linear, with apices un- 

 equally inflated. Frus- 

 tules united in a stellate 

 manner. 



Fig- 77- Asterionella fonnosa z>ar. gracillima 



