Figure 
53— 
— 186 — 
Description of Plates. 
a, @ = cellula vel semicellula a fronte visa. 
b — iar < 4 a vertice visa. 
c = Ss 5 i a latere visa. 
ad == semicellula a basi visa. 
Plate JI. 
Plewrotenium gloriosum West & G.S. West forma. >< 520. 
Gonatozygon Kinahuni Rabenh. var. tropicunt West & G. S, West, n. var. 
Closterium tumidum Johnson. Two forms. >< 520. 
Closterium acerosum Ehrenb. forma. With zygospore. >< 120. 
Clostertum Cornu Ehrenb. var. siamense West & G.S.West, n. var. > 520. 
Cylindrocystis subpyramidata West & G.S. West, n.sp. >< 520. 
Cosmarium pseudorthopunctatum West & G.S. West, n.sp. >< 520. 
Cosmarium leve Rabenh. 15 and 16, zygospores. >< 520. 
Cosmarium cequatum West & G.S. West, n.sp. >< 520. 
Cosmarinm subtriordinatum West & G.S. West forma. >< 520. 
Cosmarium subauriculatum West & G.S. West. >< 520. 
és - var. truncatum West & G.S. West, n. var. 
>< 520. 
Plate III. 
Micrasterias Mébii West & G.S. West. >< 520. 
" > var. telrachastriformis West & G. S. West, n. var, 
>< 520. 
Arthrodesmus alatus West & G.S. West, n.sp. >< 520. 
Cosmarium pseudotaxichondrum Nordst. var. siamense West & G. S. 
West, n. var. >< 520. , 
Cosmarium Schnvidiiti West & G.S. West, n. sp. >< 520. 
Staurastrum Bieneanwm Rabenh. var. orientale West & G. S. West, 
n. var. >< 520. 
pic oy hexacerum Wittr. var. tropicum West & G.S. West, n. var. 
>< 520. 
Staurastrum echinatum Bréb. >< 590. 
Staurastrum pseudotetracerum West & G.S. West var. robustwin West 
& G.S. West, n. var. >< 520. : 
Staurastrum Zahlbrucknert Liitkem. var. mamillatum. West & G.S. 
West, n. var. >< 520. : 
Staurastrum micron West & G.S. West, forma. >< 520. 
Plate 1V. 
Edogonium maximum West & G.S. West, n.sp. >< 220. 
CEdogonium dioicum Carter. >< 220. 
Spirogyra Schmidtii West & G.S. West, n sp. 43 and 44, >< 220; 
4d, >< 520. , : 
Scenedesmus acutiformis Schréder var. spinuliferiun West & G S. West, 
n. var. >< 520. 
Tetraédron bifurcum Lagerh. 
Tetraédron cruciatum West & G.S. West. >< 520. 
Reinschiella siamensis West & G.S. West, n. sp. >< 520. 
Reinschiella obesa West & G.S. West, n. sp. >< 520. 
