/Sketch of the Infusoria of the family Badllaria. 89 



by Prof. W. B. Rogers in Virginia.* Of the real nature of these 

 bodies I am quite uncertain ; they agree however with Pyxidicula, in 

 separating into two hemispherical portions. The surface is beautifully 

 marked with rows of circular or hexagonal spots or cells, resemblinof 

 those on the beautiful species of Coscinodiscus which accompany these 

 bodies in the same deposit. 



Gaillonella. 



Free, carapace simple, bivalve [siliceous), form cylindrical, 

 globular or discoid, producing chains [long articulated cylinders] 

 by imperfect spontaneous division. 



1. Gaillonella moniliformis. (PI. 2, fig. 3.) Corpuscles smooth, 

 cylindrical, short, conical at the sides and truncate, form octangular [.?] 

 circular when seen endwise, ovaries green, yL line. Ehr. Meloseira 

 moniliformis, Ktz., Linn., 1833, PI. 17, fig. 71. M. numjnuloides, 

 Grev. in Brit. Flora, V, p. 401. 



This very beautiful species grows only in salt or brackish wa- 

 ter, and occurs in great abundance in various places in the United 

 States. I first noticed it several years ago, among sjiecimens 

 of Algae from Providence, R. I. I subsequently found it almost 

 covering the bottom and shores of Providence Cove at low tide. 

 I found it again in vast quantities, in salt ditches near the railroad 

 at Stonington, Conn., where it formed large fleecy masses, some- 

 times of several feet in extent. Still more recently I have found 

 it at Staten Island, and also, much to my surprise, sixty miles up 

 the Hudson River near West Point.f 



The form is not strictly octangular, but at first appears so, in 

 consequence of the two minute projections of the delicate trans- 

 verse ridges seen near the ends of each of the two globules be- 

 longing to a joint. They do not change their form when heated 



* For an account of this truly interesting discovery, see Report on Geology of 

 Virginia for 1840. The infusorial strata of Virginia are of great interest from 

 their vast extent, and from being the first infusorial deposits noticed in this coun- 

 try, of a period tfrai!er^'or Zo the present epoch. I am indebted to Prof Rogers for 

 specimens from various localities, and with his permission I include in this memoir, 

 figures drawn by myself of several of the interesting forms found in these beds. 



t The Flora and Fauna of the Hudson River at West Point would, in a fossil 

 state, be rather puzzling to the geologist, on account of the singular mixture of 

 marine and fluviatile species. While Vallisneria and Potamogeton grow in such 

 vast quantities in many places as to prevent the passage of a boat, and the shore is 

 covered with fawiatile shells, such as Planorbis, Physa, &c. in a living state ; we 

 yet find the above fresh-water plants entangled with bunches of marine Algse, such 

 as Enteromorpha, Ectocarpus, &c., and often covered with marine parasitic zoo- 

 phytefe and marine infusoria (Achnanthes, Gaillonella, Echinella, Naunema, &.C.; 



V^ol. XLii, No. 1.— Oct,-Dec. 1841. la 



