} 
9 
26. Navicula convexa W. Smith.—Hab. New London harbormud. Rare. 
27. Navicula humerosa Brebisson.—Hab. Saguenay river, on alge. 
Long Beach, N. J., on alge. L. I. Sound, algz. Common. 
28. Navicula Hennedyii W. Smith.—Hab. Delaware river, Kaighn’s 
Point. Blue clay, fossil, Delaware river. New London, Conn., harbor mud. 
29. Navicula trochus Ehr.—Hab. Blue clay, fossil, Delaware river. 
Very rare. 
30. Navicula truncata Donkin.—Hab. Long Beach, N. J. New Lon- 
don, L. I.; alge, &c. 
31. Navicula minutula W. Snith.—Hab. Brackish marshes at Absecom 
Inlet, N. J. Cape May, salt marsh. Not uncommon. 
Differs in habitat and shape, which is more pointedly elliptic, but agrees in 
striation and all other respects with the-figure in Smith’s Synopsis. 
32. Pinnularia longa Gregory.—Hab. Providence, Fall river, on alge. 
' Newport, R. I., on alge. Rare. 
33. Pinnularia polyonca Brebisson.—Hab. Very general along the coastal 
ponds and rivers. Northam’s Pond, along with Navicula trinodis. Ogee- 
chee and Savannah rivers, on alge. Delaware river. On mud from Cooper’s 
creek, N. J., and Duck creek, Del. Our native variety often attains a length 
of -005. The figure in Mic. Journ., vol. 2, pl. iv., conveying a very poor idea 
of the size and general characters of P. polyonca, a representation of a 
full sized specimen will be found in Pl. Il. f. & 7 : 
34. Pleurosigma macrum W. Smith.—Hab. Brackish marshes at Wil- 
mington, Del., Mr. Febiger. Rare. 
35. Pleurosigma obscurum W. Smith.—Hab Brackish marshes at Dela- 
ware City, Port Penn. Marshes of Delaware City, Mr. Febiger. Rare. 
36. Pleurosigma intermedium W. Smith.—Hab. New Rochelle, on 
alge. Dredged from sea at New London. Very abundant in this locality, but 
not elsewhere. 
37. Pleurosigma rigidum W. Smith.—Hab. New Rochelle, on alge ; 
along with Pleurosigma intermedium at New London. Rare. 
38. Pleurosigma delicatulum W. Smith.—Hab. Delaware river. Rare. 
39. Licmophora splendida Ehr.—Hab. Rocks off Newport harbor, on 
alge, Mr. Powel. Common. 
40. Podosphenia Baileyi, n.sp., Edwards.—F. V. Broadly cuneate, trun- 
cate, sessile end often produced. V. Obovate, or suborbicular; the lower ex- 
tremity prolonged into a very acute point, striated; strie about 55 in 001. 
Hab.—Long Island Sound, on alge. At Stonington. New London. Black 
rock, Long Beach, N. J., on alge. Common. PI. Il. f. 8. 
This is possibly the species alluded to by Mr. Edwards, in his paper on 
American Diatomaceex, Mic. Journ., although in my specimens the presence of 
vitte is sufficiently obvious. In this early stage the frustules are imperfectly 
silicious and possess short stipes, but as the growth of the individual pro- 
gresses these become absorbed, until finally, as in others of the genus, they 
appear simply sessile. 
Since writing the above, my friend Mr. Edwards has informed me of the 
identity of this species with his P. Baile yi, (manuscript.) 
41. Gomphonema marinum.—Hab. New Haven harbor mud. Bannister’s 
_ ereek, Rockaway mud, and New Rochelle, on alge. Not uncommon. 
