ANIMAL NATURE 01' DIATOME^. 443 



length is 7'5 millim. (J^) = 0'18, and is almost four times 

 the breadth. 



Schizonema setaceum, Kiitz., (Micromega.) 



The length assigned by the author ^ig to ^ of a line = 

 0-0467 to 0-045 millim., delineated 8-2 millim. ("f^) = 

 00195. 



In an authentic specimen from Kiitzing, and in those 

 that I refer to this species, I find the NaviculEe 0-02 millim. 

 long, but considerably broader than the figures of this 

 author; the primary surfaces being 0*004, and the 

 secondary 0-07, whence the shape becomes manifestly 

 elliptical. 



Schizonema aureum, Kiitz., (Micromega.) 



Although Kiitzing has indicated no other locality than 

 Sidmouth, I refer to this species some specimens that I 

 collected at Zava, which correspond perfectly with this 

 author's description and figure. The Naviculse are 032 

 millim. long, (Kiitzing says they are ^ line = 00338 

 milhm.; and represents them 7 millim. "f = 0-0166,) and 

 are 0-006 in breadth of primary surface, and a millimilli- 

 metre more in the secondary. In this species I have 

 seen single Naviculae with swollen internal spermatia, as 

 Kiitzing delineates in his M. polyclados, to which at 

 first I thought it must belong. 



Schizonema corymbosum, Ag. 



Schizonema myxacantlium, Klitz., (Micromega.) 



The greatest length of the Naviculse, according to the 

 author, ^th of a line = 0-0492 millim. (according to the 

 figure only 0-022). To this I believe I ought to refer a 

 specimen I collected at Trieste, the Naviculae of which 

 attained 0-05 in length, and 0009 in breadth, as well in 

 the primary linear, as in the secondary elliptico-acute 

 surfaces. « 



