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MARINE AND ESTUARINE DIATOMS. 
GRAMMATOPHORA. 
Grammatophora. Frustules oblong, adhering by opposite or alternate angles 
in a zig-zag chain. Valves linear or elliptical, marked by conspicuous 
opposite septa which are usually more or less curved. 
G. serpentina E. (Plate I, Fig. 25.) Kennebecasis, La Tete, Grand Manan. 
G. marina Lyn. (Plate I, Fig. 26). Kennebecasis, La Tete, Grand Manan. 
HOMOCLADIA. 
Homocladia. (Plate I, Fig. 27). Frustules bacillar, usually somewhat 
fascicular, enclosed within submembranaceous branched filaments, 
forming a frond. 
H. filiformis W. Sm. Kennebecasis. 
HYALODISCUS. 
Hyalodiscus. Frustules simple, disc-like. The central or umbilical portion 
more or less granulated, and separated from the delicately striated 
marginal portion by a distinct suture. 
H. Sp? Passamaquoddy Bay. (Plate I, Fig. 28.) 
ISTHMIA. 
Isthmia. Frustules large, compressed, trapezoidal, conspicuously cellular, 
cohering by short neck like processes to each other or to higher algae. 
Frustules always more or less oblique. Cellules more or less hexagonal. 
I. nervosa Kutz. Passamaquoddy, La Tete. 
I. enervis Ehr. Passamaquoddy. (Plate I, Fig. 29.) 
LICMOPHORA. 
Licmophora. Frustules wedge-like, arranged in fan-like clusters on thick 
irregularly branched stipes. Valves convex, elongated, inflected at 
larger extremity and traversed by a longitudinal median line. 
L. Lyngbei Grun. (Plate I, Fig. 30.) 
L nov Sp. Kennebecasis. 
MASTOGLOIA. 
Mastogloia. Frustules oblong, boat-like, annulate, enclosed in a gelatinous 
cushion or frond. (Plate I, Fig. 31.) 
M. Smithii Thw. Kennebecasis. 
M. elliptica. Kennebecasis. 
