BULLETIN OF THE NATURAL HISTORY SOCIETY. 
237 
SYNEDRA. 
Synedra. Frustules elongated, rectangular,, attached at one end. Valves 
linear or lanceolate, plane or convex. Often grouped in fan-like radiating 
clusters. Lateral view traversed by a smooth median longitudinal line. 
S. pulchella Ktz. Kennebecasis, Passamaquoddy. 
S. acus Ktz. Kennebecasis. 
S. Ulna Ehr. Kennebecasis, Passamaquoddy. (Plate II, Figs. 30, 31, 32.) 
S. radians. Milkish, St. John river, Passamaquoddy, Grand Manan. 
S. salina. Miramichi, Campobello. 
S. sigma. Indiantown and Courtney Bay. 
TABELLARIA. 
Tabellaria. Frustules quadrangular, united into a filament or cohering in a 
zig-zag chain. Septa equal, alternate, straight. Lateral surfaces inflated 
at ends and middle. 
T. fenestrata. Kennebecasis. (Plate II, Fig. 33.) 
TRICERATIUM. 
Triceratium. Frustules free, simple, with lateral view (in N. B. species) 
markedly triangular. Surface of valves divided into cellular spaces, 
wanting at the angles which are somewhat produced. 
Tr. alternans Bail. Rare, but several specimens obtained from Harris Cove, 
Kennebecasis, and from a salt marsh at St. Martins. (Plate II, Fig. 34.) 
TRYBLIONELLA. 
Tryblionella. Frustules simple, free, elliptical or linear. Valve plain. Alae 
or wings submarginal or obsolete. Canaliculi inconspicuous, Parallel, 
small. (Plate II, Fig. 35.) 
T. scutellum Sm. Surirella circumsuta Bailey. Kennebecasis. 
T. gracilis? Kennebecasis. 
ZYGOCEROS. 
Zygoceros. This genus in general appearance closely resembles Biddulphia’ 
with which it is united by many authors. It differs in being much 
larger than the ordinary forms of the latter, not forming long chains. 
Zygoceros Mobilensis Bail. (Biddulphia Baileyi Sm.) Several individuals 
of this species were observed in the plankton of Passamaquoddy Bay 
and the Western Isles. (Plate II, Fig. 36.) 
