12 
river, in mud. Duck creek, Del., mud. Rice field mud, Savannah river. 
The variety most commonly met with is more broadly ovate than that figured 
in Mic. Journ., vol. vili., and has a wide, smooth intercostal or more proper- 
ly acostal space at the larger end of the valve. 
9. Amphiprora pulchra Bailey. Sporaugial of A. alata?—Hab. Entire 
Atlantic coast, mostly in still or stagnant salt ditches or streams. It may be 
observed of this species or variety, that in American localities it outnum- 
bers the supposed typical form, A. alata, and more than once I have found 
it in marshes where not a single frustule of A. alata has ever been seen by 
me. In the salt ditches along the Atlantic, N. J., railroad, A. pulchra is 
a very common form, the frustules ranging in size from that of A. alata to 
the largest dimensions heretofore seen in the former variety, and yet these 
smaller frustules have all the coarseness of striation and distinctive peculiari- 
ties of the largest. The same holds good at another locality, Bannister’s 
creek, Rockaway, where, as well as at Absecom, A. alata is very seldom 
met with. While, therefore, it must be acknowledged that a certain general 
resemblance, amounting almost to identity of species, exists between the two, 
it might be well, in view of the above facts, to regard A. pulchra as a fixed 
variety of A.alata, and not its sporangium. 
10. Navicula permagna Bailey. Pinnulariapermagna Bailey.—Hab. 
In most of our large Atlantic rivers and brackish marshes. At Cape May, 
salt marsh near Cold Spring, abundant. A variety, illustrating the great 
range of outline in this species, is seen in Pl. II. f.11. This is probably the Na- 
vicula esox of Kiitzing. It is more common on the Delaware river and its 
tributaries than that figured by Bailey. This form may be found exhibiting 
every range of outline between the two extremes. The striation and length 
of the frustule remains unaltered, however. 
11. Synedra undulata Bailey.—Hab. Long Island Sound. On alge 
from Newport harbor, Mr. Powel, very fine and large. Occurs in rice field 
earth, Savannah river. 
12. Tetragramma americana Bailey = (Terpsinde americana)—Hab. 
Atlantic coast of U.S. L.1. Sound, at New Haven. Black rock and Stoning- 
ton, in mud. St. Mary’s river, Ga., marsh. Delaware river, and at Bailey’s 
locality, St. Sebastian’s river, Florida. Although a widely distributed species, 
I have not found it in any abundance, except at the last named locality. Like 
Terpsinde musica it is a brackish form, although often found in fresh water 
streams. 
13. Terpsinde musica Lhr.—Hab. Southern coast, most some distance up 
tidal rivers. . Rice field mud, Savannah. St. Mary’s river, Ga. Blue clay of 
Delaware river. Very rare. 
14. Podocystis americana Bailey=(P. adriatica?)—Hab. L. I. Sound. 
Light House Point, Black Rock harbor, on alge. 
IV. Species of universal distribution along the coast. 
Epithemia musculus. | Triceratium punctatum. 
Cocconeis scutellum. | Cyclotella Kiitzingiana. 
Coscinodiscus subtilis. | rotula. 
radiat Ts: operculata. 
eccentricus. | Surirella fastuosa. 
oculus-iridis. gemma. 
Eupodiscus argus. | striatula. 
sculptus. ovata. 
Triceratium favus. salina. 
alternans. angusta. 
