Sketch of the Infusoria of the family Bacillaria, 321 
Art. V.—Sketch of the Infusoria of the family Bacillaria ; by 
J. W. Battey, Professor of Chemistry, &c. in the U. S. Mili- 
tary Academy. 
Part UL 
Tue animalcules which form the subject of this part of my 
sketch of American Bacillaria, belong to the sections Echinellea 
and Lacernata. 
The section Echinellea contains those Bacillaria which are fied, 
that is, attached either by their extremities, or by a Pac. to 
other bodies. They are all siliceous. 
The section Lacernata includes those which have a double 
covering. ‘They consist of groups of siliceous individuals, sur- 
tounded by a common gelatinous mass, or enveloped by a mem- 
branous tube. 
As many species of each of these sections are often found spon- 
taneously or accidentally separated from their pedicels or tubes, 
there is great chance of mistaking them for species of Navicula- 
cea, 
Secr. Il. ECHINELLEA. 
IstHMIA. ~ 
Fived by one end, carapace or lorica siliceous, simple, broader 
than long, catenate by imperfect spontaneous division, individuals 
making various angles with each meee and connected by a nar- 
stad isthmus or neck-like process. 
Two species of this genus inte been detected, viz. I. enervis, 
and J. obliquata. Neither of these have, to my knowledge, yet 
been detected in the United States; but as the latter is a pelagic 
species which has been found in places so different and distant 
from each other as Iceland, England,. the Canary Islands, Cape 
of Good Hope, &c. there can be little doubt that it will yet be 
found growing on some of our marine Alge. The first specimen 
which I ever saw, I detected on a dry specimen of Odonthalia 
dentata from Iceland. I have since received fine English speci+ 
mens from E. J. Quekett, Esq. of London. Few mnICTORCOpES 
objects “exceed in beauty these little gems of the ocean. I have 
Ptoved that their carapace is siliceous by the proper | 
Vol, xt1m, No. 2.—July—Sept. 1842. 4} 
