The desmid flora of Nantucket 



Joseph Augustine Cushman 



The island of Nantucket, from its location some little distance 

 off the coast of Cape Cod, and its many large ponds, seems to be 

 worthy of an investigation in the line of its microscopic flora. It 

 is essentially a sandy soil that characterizes the island, and accord- 

 ing to previous work on this group of plants a rich flora was not 

 expected, loose sandy soil usually not being rich in desniids com- 

 pared to a rocky region. The ponds of the island are open to 

 the sunlight in all their parts, for trees are not a Nantucket char- 

 acteristic. They are therefore well lighted in the shallow water 

 from which the collections here worked up were taken. For an 

 opportunity to study the contents of these ponds and swamps I 

 have to thank several members of the Nantucket Maria Mitchell 

 Association who very willingly undertook the task of collecting 

 from the various ponds of the island. In all nearly fifty bottles 

 of material were collected, from the last, of April to the first week 

 of June being the range of dates. The whole number of species 

 (over fifty) may not seem very large, but many of the forms were 

 very common and well scattered over the island. Certain of the 

 forms are new to the New England flora and such are starred. 



Mesotaenium Nag. 1S49 

 M. MACROCOCCUM (Kiitz.) Roy & Biss. Lat. i8/^ : long. 38 /i. 



Gibb's Pond. 



Cylindrocystis Menegh. 1838 



C. Brebissonh Menegh. Long. 50 /i : lat. 18//. Tom Never's 

 Pond. 



C Brebissoni minor W. & G. S. West. Long. 32/^: lat. 

 12/^ Great Miox's Pond. 



Netrium Nag. 1849 

 . N. Digitus (Ehrenb.) Itzigs. & Rothe. Long. 99- 1 86 /i : lat. 

 med. 34-65 /i: apex 14-21 /i. Gibb's Pond, Wigwam Pond^ 



Almanac Pond. 



549 



