150 TUFTS COLLEGE STUDIES, VOL. II, No. 3 



2. C. SIEBOLDII A. Braun in Kiitzing, 1849, p. 208; 1855, 

 p. 32, PI. III. A. ; G. S. West, 1905, p. 286. Cells 15-25X4-9 n\ 

 erect, straight, when young elongate-ellipsoid or lanceolate, 

 rather obtuse ; when adult short ellipsoid or obovoid, obtuse ; 

 stipe short, without basal disk. Barbados. Europe. 



3. C. NAEGELII A. Braun in Nageli, 1848, p. 86, PI. III. 

 D. ; Wolle, 1887, p. 178, PI. CUX, fig. 4; Rabenhorst, Algen, 

 No. 512. Cells 20-42X7-18 /x, erect, straight, at first narrowly 

 lanceolate, later oblong or ellipsoid, always obtuse; stipe 

 slender, about 4^ long, base not swollen. Mass., Pa., Neb. 



Europe. 



4. C. STRICTUM A. Braun, 1855, p. 37, PI. V. A. ; P. B.-A. 

 No. 1371. Cells 23-30X6-7 fj., narrowly lanceolate or linear- 

 oblong, straight, apex obtuse or rounded ; stipe very short, 

 slightly swollen at the base. Mass., Cal. Europe. 



5. C. HETEROMORPHUM (Reinsch) Wolle, 1887, p. 178, PI. 

 CUX, fig. 6; Hydnanum heteromorphum Reinsch, 1875, p. 

 80, PI. XI, fig. 3. Cells 20X8-18 fji, globose to ellipsoid, taper- 

 ing below into the stipe ; zoospores escaping by a wide opening 

 at the summit ; cell after escape of the zoospores subcylindrical, 

 about 6 fj. diam. Pa. Europe. 



It may be a question whether the cell continues to live after 

 the emission of the zoospores; Reinsch's brief note does not 

 give sufficient information. 



6. C. OBTUSUM A. Braun, 1855, p. 39, PL III.E. Cell 

 straight, 22-33 P- long, at first oblong-ellipsoid, later broadly 

 ovoid and about half as broad as long ; with a rounded stopper- 

 like body at the apex of the cell ; stipe very short, slightly 

 thickened at the base. Mass. Europe. 



7. C. AMBIGUUM Hermann, 1863, p. 26, PI. VII, fig. 9; 

 Wolle, 1887, p. 177, PI. CUX, fig. 5. Cells 24-32X4-8 /x, 

 erect, obliquely and narrowly lanceolate or ensiform, uniformly 

 attenuate to each end, apex cuspidate, with a sometimes curved 

 apiculum ; stipe short, slender, not swollen at the base. Mass., 

 Pa. Europe. 



8. C. De Baryanum (Reinsch) nov. comb. ; Dadylococcus De 

 Baryanus Reinsch ,1875, p. 78, PI. XI, fig. i ; i879a, p. 38. PL 

 I, figs. 21-24. Cells oblong to ovoid, 20-25X30-40 /*, with rela- 

 tively stout stipe, about 15 /* long, swollen at the point of 

 attachment into a small, thick disk. On the minute crustacean, 

 Cyclops. Mass., Mich. Europe. 



Reinsch records observing the development of the mature 

 plant just described from a motile cell about 25 p. diam., with 



