TRANSACTIONS OF MICROSCOPICAL SOCIETY. 
DESCRIPTION OF PLATE IV, 
Illustrating Dr. Greville^s paper on New Diatoms, Series I. 
Fig. 
1. — Stidodiscus Bury anus t focused for the radiating lines. 
2. — The same, focused to show tlie plicate character of the disc. 
3. — S. Johnsonianus. 
4. — S. insignis, X 600. 
5. — Coscinodiscus armatus. 
6. — C. tuherculahis. 
7. — C. biradiatus, 
8. — C. elegantulus. 
9. — C. Barbadensis. 
10. — Triceratium capitatum. 
11. — T. Westianum. 
12. — T. Barbadense. 
13. — T. nitidum. 
14. — T. cellulosum. 
All the figures are X 400, except fig. 4, which is x 600 diameters. 
The Barbadoes species are described from a fine series of slides supplied 
by Mr. J. T. Norman. 
