TRANSACTIONS OF MICROSCOPICAL SOCIETY. 
DESCRIPTION OF PLATES III, IV, 
Illustrating Dr. Greville^s monograpli of the Genus 
Asterolam'pra, 
PLATE III. 
Kg. 
1 to 4. — Asterolamjpra Marylandica. 
5. — A. rotula. 
6 to 8. — A, variabilis. 
9. — A. Brebissoniana. 
PLATE IV. 
10. — A. Dallasiana. 
11. — A. Wallichiana. 
12. 13. — A. Barwinii. 
14. — A. Roper iana. 
15. — A, Hiltoniana. 
16. — A. elegans. 
17. — A. imbricata, 
18. — A. BrooJcei. 
19. — A. ShadboUiana. 
20. — A. stellata. 
21. — A. Orevillii^ showing an abnormal arrangement of the umbilical lines. 
In consequence of an error arising out of the use of a new objective, 
some of the figures are more than x 400 diameters, but are drawn to the 
same scale. Eortunately, the range of size in the species is often so very 
great, the error is not of material importance. The measurements in the 
descriptions are all x 400 diameters. 
Pigs. 14, 16, 17, 18, 19 and 20 are X 400 diameters. 
As the areolation or cellulation of the segments is essentially similar in 
all the species, differing only in degree, and often almost imperceptibly so, 
it has not been considered necessary to add largely to the labour of the 
engraver, by filling up the segments with so much minute work. 
