382 : Sketch of the Infusoria of the family. Bacillaria. 
Fig. 7. Gomphonema 
rine, Stonington, Conn. 
Fig. 8. Echinella flabellata, a single group. Fig. 8, 4, a sketch of 
several groups slightly magnified, drawn from the living specimen. Ma- 
rine, Stonington, Conn. 
Fig. 9. Echinella , @ group parasitic on an aquatic plant. Fig. 
9, a, b, different positions of a single frustule. Hudson River. 
Fig. 10. Cocconema , group supported on the branching pedi- 
cel. Hudson River. 
Fig. 11. Cocconema 
rated from its pedicel. 
Fig. 12. Achnanthes brevipes, several groups parasitic on a Con- 
ferva; b, a larger pair; c, back view. Stonington, Conn., Hudson Riv- 
% 7 a, another view of a frustule. Ma- 
° é 
, a, b, two positions of an individual sepa- 
r, &c. 
Fig. 13. Striatella arcuata. Marine, Stonington, Conn. 
Fig. 14. Naunema , a, b, two positions of the frustule separated 
from its tube. Marine, Staten Island, N. Y. 
Fig. 15. Naune , a, frustule separate from its tube. Ston- 
ington, Conn. * 
Fig. 16. Naunema , a,b, two positions of a single frustule. 
Stonington, Conn. 
Fig. 17. Naunema , group of frustules within their tube. West 
Point, N. Y. 
Fig. 17, a. Naunema , single frustule. West Point. 
- Fig. 18, a to d. Spicule of Spongilla or fresh-water sponge. 
Fig. 19, a, b. Probably spicule of another species of Spongilla. b, 
group of three individuals. 
Fig. 20. Amphidiscus rotula of Ehrenberg, probably derived from 
a Spongilla. Fossil at West Point, near Boston, Wrentham, &c., also 
7 in South America. , 
Fig. 21 to 23. Siliceous bodies of organic origin, found with fossil 
fresh-water infusoria. ; 
Fig. 24. Dictyocha fibula? Ehr., common among fossil marine infu 
soria in the infusorial stratum of Virginia at Richmond and Rappahan- 
nock cliffs. 
- Fig. 25. Fragment of the preceding. 
Fig. 26. Dictyocha speculum, Ehr., with the preceding. 
© Fig. 27 and 28. Siliceous bodies, found with the preceding. 
Fig. 29. Binary, triangular, siliceous bodies, found with the prece- 
. ae te sa : ‘ : P 
‘Fig. 30 to 35. Siliceous spicule, &c. probably derived from marine af 
sponges or Actinia, found with the preceding. 
e sho wing yyoths ths of a i 
of a millimetre, magnified equally 
