— 171 — 
guished from the typical form by the reduced lobules of the lateral lobes 
and the greater attenuation of each extremity of the polar lobe. It re- 
ceives its name from its resemblance to those species of Micrusterias 
which were at one time placed under Teérachastrwum. 
55. M. retata Ralfs in Ann. Mag. Nat. Hist. V, 1844, p. 299, t. VI, 
f.1; Brit. Desm. 1848, p. 71, t. VIII, f.1. 
In stagnant water in the jungle. 
Area: Europe, N. and S. America. India, Singapore. Japan. 
Cosmarium Corda. 
56. ¢€. psendopyramidatum Lund. in Nova Acta R. Soc. Scient. Up- 
sala, ser. 3, VIII, 1871, p.41, t. IL, f. 18. 
Long. 54 yz; lat. 36; lat. isthm. 11 p. 
Area: General in temperate and tropical climates. 
57. €. leve Rabenh. Flor. Europ. Algar. Ill, 1868, p. 161; Nord- 
stedt in Ofvers. af K. Vet.-Akad. Férh. 1876, no. 6, p. 29, t. XII, f. 4; 
G. 5. West in Journ. Linn. Soc. bot. 1899. (Tab. nostr. II, fig. 14.) 
Long. 22—25 2; lat. 16—19,5 7; lat.isthm. 5,8—6,72; crass.9—10 p. 
Zygospore angulari-globose, glabre, angulis leviter incrassatis. Diam. 
zygosp. 22—25y. (Tab. nostr. II, fig. 15—16). 
This occured in enormous quantity on rocks in a riverbed and the 
zygospores were abundant. We have previously described what we then 
thought to be this plant in zygospore (cfr. West & G. S. West in Journ. 
Roy. Micr. Soc. 1896, p. 154—5, t. IV, f. 35; West in Notarisia 1892, 
p. 1502), but we can now definitely say that is was not. The Cosmariwm 
we described from Portugal as_C. lave with zygospores (,zygospore glo- 
bose’ spinis brevibus numerosis truncatis bifidisve ornate“) is certainly 
not C. leve Rabenh., but some other closely allied species with smooth 
cells and a spiny zygospore. We are sure of this because we have now 
obtained C. leve Rabenh. in zygospore in such great quantity. 
Area: Europe, N. and S, America, E, and W. Africa, Madagascar, India, 
Ceylon, E. Indies, New Zealand and Australia. 
58. (¢. pseudonitidulum Nordst. in Acta Univ. Lund. IX, 1873, p. 16, 
t. 1, f. 4. 
Long. 37 #2; lat. 25; lat. isthm. 7,5; crass. 16 u. 
All the forms seen were very delicately punctate. 
In stagnant water in riverbed amongst Spirogyra gracilis. Also among 
Utricularia in riverbed. 
Area: Europe, Gentral China. 
59. €. obsoletum Reinsch in Abhandl. Senckenb. naturf. Gesellsch. 
VI, 1867, p. 142, t. XXII DI, f. 1—4; in Abhandl. Naturhist. Gesellsch. 
zu Niirnberg Ill, 167, p. 184, t. XII, f. 4. C. palustre Turner in Kongl. 
