CusHMAN: Nores on MICRASTERIAS 395 
cies is very great, but according to W. and G. S. West this varia- 
bility is limited to American specimens. 
M. AMERICANA (Ehrb.) Ralfs. 
The typical form was obtained from a pond at Plainville and 
also from Carver’s Pond, Bridgewater. An average specimen 
from Plainville measured long. 155 y, lat. 130», lat. lob. pol. c. 
proc. 544, lat. isth. 28 w. One from Bridgewater, long. 158 y, 
lat. 133 y, lat. isth. 22 y, lat. lob. pol. c. proc. 50 
M. AMERICANA RECTA Wolle. 
This variety was noted from Carver’s Pond, Bridgewater, but 
measurements were not obtained. 
M. AMERICANA spinulifera var. nov. 
End lobe short and in general appearance much like var. 
Ralfsti Maskell. Not as spinose as var. spinosa Turner and with- 
out the “spinose coronet”’ of that form. Considerably smaller 
than the typical form and slightly smaller than the var. spinosa. 
Ends of the lobes spinose, also two subcentral spines at the basal 
Margins. Long. 120 , lat. 108 y, lat. isth. 25 y, lat. lob. pol. c. 
proc. 57 y, lat. lob. pol. s. proc. 33 4. From Stub Pond, three 
miles northeast of Fall River R. R. Station. 
M. tarticers forma MAJOR Nordst. 
Found both in Carver’s Pond and in Lake Watuppa. A speci- 
men from the latter measured long. 150 y, lat. 165 /, lat. isth. 37 p. 
i 
M. MAHABULESHWARENSIS COMPACTA, a. AMERICANA Nordst. 
Noted from Carver’s Pond, Bridgewater in the previous list. 
M. rruncata (Corda) Bréb. 
The typical form was found in a pond at Chilmark, Martha's 
Vineyard and in Lake Watuppa. A specimen from the former 
locality measured long. 113 4, lat. 1104, lat. lob. pol. 814. A 
Watuppa specimen, long. 100 p, lat. 93 y, lat. lob. pol. 55, lat. 
isth. 192. Although this species is supposed to be very common 
it was found in but these two localities. 
M. pEepauperATA Nordst. 
The typical species, FIGURE I, was described by Nordstedt 
from Brazil, the measurements of the original, as given by the au- 
