30 T. H. BUFFHAM ON CONJUGATION OF ORTHONEIS BINOTATA. 



I submitted specimens of Orthoneis hinotata in situ to several 

 diatomists of wide experience, who, however, had never seen it. 

 I have pleasure in acknowledging my indebtedness to Mr. 

 Thos. Comber, F.L.S., who, following a slight clue, tracked it 

 down to the authorities I have thus, through his kind assist- 

 ance, been enabled to quote. 



I may be permitted to add here a short note on conjugation 

 of Rhahdonema arcnatum Kiitz. {Journ. Queh. Mic. Cluh, Vol. 

 ii, Ser. ii, p. 131.) In a gathering sent me by Mr. W. H. 

 Shrubsole, of Sheerness, in Jan. 1889 I found all my former 

 conclusions amply confirmed. But — what was more interesting 

 — I noted at the same time three small specimens of Bh. 

 minutum Kiitz. only 18 fx wide (=-0007 inch). All of them 

 had the small frustules attached laterally, which in Uh. 

 arcuatum I considered males ;* and two of the specimens bore 

 single sporangia. These, pro tanto, confirm my former results, 

 and show that the phenomena are generic. 



Explanation op Plate III. 

 Orthoneis hinotata Grunow. 



Fig. 5. — Inner side of valve with plates projecting from the 



edges. X 800. 

 „ 6. — Ideal transverse section of the same, x 800. 

 „ 7. — A frustule in very early stage of perigloea (girdle or 



zonal view). x 400. 

 „ 8. — The same more advanced. A short, thin tentaculoid 



passing through the mammiform protuberance. 

 X 400. 

 „ 9. — Vertical or valve view of mature frustule in which 



the tentaculoids are seen to originate from the 



plates. X 400. 

 „ 10. — Girdle or zonal view of a pair of frustules, the result 



of self-division, x 400. 

 „ 11. — Mature sporangium containing two sporangial 



frustules and the four old valves, x 400. 



* In Bennett and Murray's Cryptogamic Botany, p. 423, 1 am incorrectly 

 reported as describing the male frustules attaching themselves to any part 

 " of the girdle " of the female frustule. The words " of the girdle " are quiire 

 contrary to my statement and should be omitted. 



