SPECIES OF UESMIDS. 85 



k. Ends separated 7-10 times the diameter; width -j-i-j- to -yhws '"• 



(25-28/i) . acuminatum, 44 



k. Cell 6 to 8 times longer than wide, ends obtuse; width yTyVi" ^'^• 



(14/^) Jenneri, 44 



k. Cell 6 to 8 times longer than wide, ends obtuse; width ^^r ^ in. 



(i2yu) . par-vulum, 45 



/4. Cell 8 to 12 times longer than wide, nearly semicircular, ends 



sharp; width -g-^ to -^^ in. (8-ioyu) , . Venus, 44 



/. Cell stout, ends broadly rounded; width -gJ^ to ^^^^^ in. (25-3o/<), 



cucumis, 40 

 w2. Beaks slender, nearly as long as the body, ends obtuse, curved, 



Kuetzingii, 47 

 711. Beaks thin, y^. as long as the fusiform body rostratum, 46 



14. DOCIDIUM. FIG. 14. 



§ Suture a projecting or conspicuous rim [a). 



§ Suture not projecting [d). 



a. Cytioderm hirsute; semi-cell with 3 or 4 undulations, spinosmn, 51 



a. Cytioderm not hirsute {b). 



b. End dentate or crenate; semi-cell with i basal inflation (c). 



b. " " '' " semi-cell with 4 regular inflations; teeth 



on the margin , . . constrictum, 50 



b, End dentate or crenate; semi-cell with 3 or more inflations; teeth 



below the margin . . nodulosum* 



b. End truncate or rounded; semi-cell with i or 2 basal inflations, 



Trabecula, 48; tnincatum, 48 

 b. " ■' " " semi-cell undulate to the contracted end, 



crenitlatum, 47 



b. " " " '• " 1-2 undulate at base only, 



Archerii.*' 



c. End with i tooth on each angle Flowtnvii, 49 



c. End crenulate with tubercles . coronatum, 49 



d. Cytioderm hirsute; base of semi-cell slightly inflated, hirstUuni, 51 



d. Cytioderm not hirsute (e). 



e. End dentate or crenate (/). 



e. End not dentate nor crenate (7). 



f. Semi-cell with 4 or more inflations (K). 



f. " with whorls of quadrangular prominences, 



%>errucosmn, 52 



/. " with 20 or more constrictions . . cosiatitm, 5 3 



/. " with I inflation (^). 



*F.-w. Algs, p. 25. 



