Desmids from southwestern Colorado 
Jos—EpH A. CUSHMAN 
(WITH PLATE 7) 
The material in. which the desmid forms here noted were con- 
tained was collected in July, 1903, by Mr. Walter S. Tower. 
The amount of material was small and not at all rich. It was 
from moss growing at the edge of a small lake about a hundred 
yards wide, at the head of Tank Creek. This stream is a tribu- 
tary of the Animas and runs into the river about six miles below 
Needleton, Colorado. The altitude of the lake was 3,540 meters. 
At this altitude, where vegetation was not at all abundant, several 
genera of desmids were found. .None of the filamentous forms 
were noted, however. Several of the forms are not typical and 
differ from the described varieties. The following species were 
noted (the numbers given with each species, H. C. mo. 422, etc., 
have reference to the numbered slides in the author's herbarium) : 
Pentum Dicrrus (Ehrenb.) Bréb. in Ralfs, Brit. Desm. 150. A/. 25. 
J. 3. 1848. (PLATE 7, FIGURE I.) 
Long, 215 y; lat. 65. A truncate from very much like that 
figured by Wolle, Desm. U. S. ed. 2. pl. 6g.f. 7. (H.C. 
20. 428.) 
Penium closterioides spirogranatum var. nov. (PLATE 7, 
FIGURE 2.) 
Long. 138; lat. 33. Apices granulate, middle portion 
with an irregular granular spiral band connecting the apical 
portions. (H.C. no. 426.) 
Cytinprocystis Americana W. & G. S. West, Jour. Linn. Soc. 
Bot. 33: 281. pl. 18. f. 5,6. 1898. (PLATE 7, FIGURE 
Long. 53; lat. 2 5. The specimen in every way fits the 
description and figure. The original specimen was from 
Ithaca, N.Y. (H.C. no. 426.) 
CLosteRium sTRIOLATUM ERECTUM forma f Klebs, Schrift. Phys.- 
Oekon. Gesells. K6nigsberg, 22: 14, p/. 2.f. 10. 1879. 
Long. 3304; lat. 304; lat. apic. 15. (H. C. wo. 426.) 
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