JOURNAL OF MICROSCOPICAL SCIENCE. 



DESCRIPTION OF PLATE XII, 



To illustrate Mr. Archer's papers. 



Figs. 

 1 — 10. — Different views of Micrasterias Thomasiana. 



11 — 15. — Views of Cosmarium tuberculatum. 



16 — 22. — Views of Staurastrum lanceolatum. 



23 & 24. — Views of Closterium directum. 



25 — 27. — Views of Closterium Pritchardianum. 



28 — 31. — Views oi Spirotcenia truncata. 



32—43. — Views of Spirotcenia parvula. 



44 — 62. — Views of Ankistrodesmus acutissimtis. 



