124 Oh Fossil Infusoria, discovered iji Peat-earth, Sj-c. 



With regard to the question concerning the animal or vege- 

 table nature of the BacillaricB, I can add nothing new to the 

 testimony of those who support their animal nature. I have often 

 witnessed the motions of several species of Bacillarias, and would 

 no more think of referring them to the action of electricity, 'than 

 I would the more active, buf apparently not more voluntary 

 movements of Vibrio, or Rotatoria. I have seen them advance, 

 and recede, vibrate to the right and left, push against obstacles, 

 and in case they could not pass them, retreat and 'go round them. 

 It must be a very curious electric arrangement, that can produce 

 such actions as these. 



Note.— I have taken considerable pains to distribute specimens 

 of the Fossil Infusoria, &c., above referred to, but those who have 

 not received specimens, and are interested in these matters, may 

 obtain them from Prof. SiUiman, to whom I have sent a large 

 supply, from Dr. J. R. Chilton, New York, from O. Mason, Esq., 

 Providence, R. I., and from myself at West Point, N. Y. 



EXPLANATION OJP PLATE II. 



Fig. 1. One of the fossi! Infusoria found at West Point, which appears identical 

 with specimens from Ehrenberg. 



Fig. 2. Another species, which is also very abundant in the peat-earth. — N. B. 

 The fine parallel transverse lines are marks upon the shell, which are easily seen 

 with a high magnifying power. The figures represent these objects as magnified 

 about three hundred and fifty times in length. 



Fig. 3. A smooth round siliceous body, apparently solid and without any marks. 

 Very abundant in the_ peat-earth. 



Fitr. 4. A round solid siliceous body, having numerous asperities. Less abundant 

 than the preceding. 



Fig. 5. Siliceous shell of a common species of Infusoria. 



Figs. 7, 8, and 9. Siliceous shells of small Infusoria. The motions of the living 

 species of Figs. 7 and 8, are more active than those of any of this tribe that I have 

 witnessed. The motions of the species represented by Fig. 5, are also very evident. 



Fig. 10. A portion of peat-earth diffused in a drop of water, and moderately 

 magnified (about fifty times.) This shows imperfectly, the immense number, and 

 variety of forms, which exist in the peat-earth. 



Fig. 12. Diatovia flocculosum. Very common in brooks, &c., among Confervee. 



Fig. 12 a. an articulation of the same more highly magnified. 



Fig. 13. Diatoma tenue ? Found with the preceding species. 



Fig. 13 a. An articulation of the same more highly magnified. 



Fig. 14. Diatoma crystallinum? Straight, smooth, siliceous tubes, occurring in 

 great quantities in small streams, near West Point, closely resembling foreign speci- 

 mens of D. crystallinum. 



Fig. 15. Fragillaria pectinalis. a, h, specimens differing in the width of the 

 articulations, c, articulations highly magnified. 



Fig. 16. Meridian vernale? from Washington's valley, near West Point, a, ar- 

 ticulations highly magnified. 



