BURSARIA. INFUSORIA. 449 



ORDER II. INFUSORIA NUDA. 



Body very simple, microscopical, destitute of organs or exterior 

 appendages, and appearing homogeneous. 



The naked Infusoria are animalcules of very simple organization, the greater part 

 of them transparent and extremely minute, appearing even with the assistance of 

 the microscope but as moving points. They are always found in water which has 

 been for some time exposed to the heat of the air or sun, and above all in water in 

 which animal or vegetable matters have been infused. Lamarck divides them into 

 two sections, as the body seems consistent, or merely membranous. 



SECTION I. 



Body membranous, almost without thickness, flattened or con- 

 cave. 



Gen. 1. BURSAIIIA, Lam. 

 Body very simple, membranous, concave. 



B. truncaiella, Lam. Follicular, with the apex truncated. Found 

 in the water of ditches. Mull. Inf. pi. 17, fig. 14. 



B. Irirundinella, Lam. Laciniate on hoth sides, the extremities 

 produced. Inhabits water of marshes. Mull. Inf. pi. 17, fig- 

 9-12. 



Gen. 2. KOLPODA, Lam. 



Body very minute, very simple, flattened, oblong, sinuous, irre- 

 gular, transparent. 



K. lamella, Lam. Elongated, membranaceous, curved before. 

 Mull Inf. pi. 13, fig. 1, 5. 



K. gallinula, Lam. Oblong, the fore part of the back hyaline. In 

 sea water which has been kept. Mull. Inf. pi. 13, fig. 6. 



K. striata, Lam. Oblong, subarcuate, depressed, white, acuminat- 

 ed before, and rounded behind. In sea water. Mull. Inf. pi. 

 13, fig. 16, 17. 



Gen. 3. PARAMECIUM, Lam. 

 Body very small, simple, transparent, membranous, oblong. 



The animalcules of this genus are less sinuous, angular, and irregular than the pre- 

 ceding. 



P. aurelia, Lam. Compressed, acute behind. Inhabits ditches where 

 the Lemna grows. Mull. Inf. pi. 12, fig. 1, 14. 



P. chrysalis, Lam. Cylindrical, plicated towards the fore part, ob- 

 tuse behind. Found in sea water in autumn. Mull. Inf. pi. 

 12, fig. 15. 



Gen. 4. CYCLIDIUM, Lam. 



Body very minute, simple, transparent, flattened, orbicular, or 

 oval. 



C. bulla, Lam. Orbicular, hyaline. Found in infusion of hay. 

 Mull pi. 11, fig. 1. 



VOL, II. F f 



