BULLETIN OF THE NATURAL HISTORY SOCIETY. 
231 
ENCYONEMA. 
Encyonema. Frustules cymbiform, arranged in longitudinal series within 
submembranous tubular filaments producing a frond. Valves divided 
unequally by median line and nodules. Striae moniliform. (Plate I. 
Fig. 19.) 
E. caespitosum Kutz. Kennebecasis. 
E. ventricosum K. Kennebecasis. 
EPITHEMIA. 
Epithemia. Frustules quadrilateral, lunately curved, with transverse ribs. 
Strongly marked transverse lines. 
E. turgida Ehr. Kennebecasis. (Plate I, Fig. 20.) 
E. gibba Kutz. Kennebecasis. 
E. zebra Ehr. Kennebecasis. (Plate I, Fig. 21.) 
E. musculus Ktz. Kennebecasis. Passamaquoddy. 
EUNOTIA. 
Eunotia. Frustules free, oblong. Valves arcuate, with terminal nodules and 
convergent striae. 
E. monodon Ehr. Kennebecasis. 
E. diodon Ehr. Kennebecasis. (Plate I, Fig. 22.) 
E. major. Kennebecasis. 
E. pectinalis. Kennebecasis. 
E. lunaria. Kennebecasis. 
FRAGILLARIA. 
Fragillaria. Frustules linear, straight. United into a filament, free or at- 
tached. Valves linear or elliptical, smooth or finely striated. (Plate I, 
Fig. 33.) 
F. Sp? Passamaquoddy. 
F. pacinca? Grun. Kennebecasis. 
F. construens? Grun. Kennebecasis. 
F. mutabilis? Grun. Kennebecasis. 
GOMPHONEMA. 
Gomphonema. Frustules stipitate, wedge-form. Valves variable in outline, 
striated, with median line and central nodule. 
G. acuminatum Ehr. Kennebecasis. 
G. angustatun. Kennebecasis. 
G. exiguum K. Kennebecasis. 
G. marinum. Passamaquoddy, Grand Manan. 
G. geminatun A. Kennebecasis. (Plate I, Fig. 24.) 
