288 
C. tenue Arch. (common almost everywhere). Often found in 
quantity and usually with zygospores. I believe it is the form de- 
scribed and figured by Wolle as C. dioculatum Breb. It cannot 
be that species, for it has smooth zygospores (see Wolle’s figure, 
Desmids of the U. S., Pl. XVIIL., Fig. 22). 5 
C. triplicatum Wolle (Conn. and Ann Arbor, Mich). 
C. tessellatum (Delp.) Nordst. (Ann Arbor, Mich.), Fig. 17. 
This is one of the most interesting species found. Only a single 
specimen was found, but that was in fine condition and agreed 
exactly with Delponte’s figures and measurements. This speci- 
men measured 68 x 140 #. It has not before been found here. 
In addition to this species the following are new to the United 
States. 
C. calcareum Wittr., C. cyclicum Lund., C. subglobosum, Nordst, 
C. subspeciosum Nordst., C. sulcatum Nordst. » It is interesting 
to note that of the new species described by Nordstedt from the 
Sandwich Islands, three have now been found in this country. 
They are C. anisochondrum, C. sulglobosum and C. sulcatum. 
Staurastrum aspinosum Wolle was found abundantly in Com — 
necticut and New York. Other interesting species are: 
St. megacanthum Lund. (Conn.). Quite rare. 
St. cuspidatum Breb. (Conn.). Only occasionally seen. 
St. Hystrix Ralfs. (N. Y.). Scarce. 
"St. incisum Wolle (Edgemoor, Ind., Conn., and Ann Arbor, — 
Mich.). My determination of this was confirmed by Mr. sb 
Specimens have several times been found with one semi-ce 
typical and the other exactly like St. crenulatum (Naeg-) Delp. PS 
St. irregulare West (Conn., N. Y.), Fig. 10. I refer here: 
small species which I have had under observation for seve 
years. Since the plate for this paper was prepared this speci¢s 
has been described by W. West in the Journal of the Royal Mict- es 
_ Society for 1894. I have not yet seen the paper, but through the A 
kindness of Prof. Nordstedt have received tracings of the figans*: A 
The American specimens average 18-20 win diameter (with the - 
rays), and 20-25 » in length; isthmus 6 /. = : ; 
St. leptocladum Nordst. (N. Y. and Ann Arbor, Mich.), Fig: ? 
The specimens are not exactly like Nordstedt’s figures. || 
: rH ee, ea iy tract 
| Desmidiae Brasiliae. Aftryk af vidensk. Medd, fra den Naturh. Forening | 
Kbhyn., p- 218, FE. 4, Fig, SF (1869). Saar 
