od XXV 
DESCRIPTION OF PLATE IV. 
Various species of recent Diatomacee, to illustrate the Fossil remains of this 
Tribe of Vegetables. 
For detailed descriptions, see pages 87—100. 
Figs. 1 to 5.—Various kinds of Xanthidia: figs. 2, 3, 4, found in a pond on 
Clapham Common, and fig. 1. living in a pond near Westpoint, United 
States. 
1.—Xanthidium furcatum: 3; ofa line in diameter. 
2,— ———_—_—_ hirsutum: 3 
3.— —————-_ aculeatum: 3 
4,.— ———__—__ fasciculatum : 3. 
5.— ——___________—__ variety of the above. 
2*,.—Pyxidicula operculata; Carlsbad, Bohemia: 3, of a line in diameter. 
6.—Bacillaria vulgaris. #; of a line in diameter. Pond on Clapham 
om | 
* 
Lal 
° 
Common. 
7.—Cocconeis scutellum: from the Baltic: > ofa line. 
8.—Navicula viridis: 4 of aline. Ponds on Clapham Common. 
9.—The same; aside view; showing the currents produced in the water 
by the animal when in locomotion. 
10.—Gallionella lineata: 3, ofa line. Ponds on Clapham Common. 
11.—Gallionella moniliformis: 3, of a line. 
12. Synhedra ulna: 3 of a line: the point a, marks the pedicle of attach- 
ment. Ponds on Clapham and Wandsworth Commons. 
13.—Podosphenia gracilis: 3, of a line; attached to a thread of Calothria. 
and having by self-division formed a radiating cluster. Common in the 
ditches communicating with the Thames in Battersea-fields. 
14.—Navicula splendida : jz of a line in diameter. 
15.—Lateral view of the same. 
