ANIMAL NATURE OF DIATOME^E. 443 



length is 7'5 millim. (^) = (H8, and is almost four times 

 the breadth. 



Schizonema setaceum, Kiitz., (Micromega.) 



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

 0-0467 to 0-045 millim., delineated 8-2 millim. ( 4 ^) = 

 0-0195. 



In an authentic specimen from Kiitzing, and in those 

 that I refer to this species, I find the Naviculae 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. 



Sckizonema 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 Naviculas are 0'032 

 millim. long, (Kiitzing says they are ^ line = 0'0338 

 millim.; and represents them 7 millim. T = 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 Naviculse with swollen internal spermatia, as 

 Kiitzing delineates in his M. poly dados, to which at 

 first I thought it must belong. 



* Ag. 

 Schizonema myacacanthum, Kiitz., (Micromega.) 



The greatest length of the Naviculse, according to the 

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

 figure only O022). To this I believe I ought to refer a 

 specimen I collected at Trieste, the Naviculae of which 

 attained 0'05 in length, and O'OOO in breadth, as well in 

 the primary linear, as in the secondary elliptico-acute 

 surfaces. 



