VAMPYBELLIDA. 95 



Body discoid, granular and reddish as in the preceding 

 genus, variable in outline, usually oval, consisting of 

 a mobile endoplasm which contains numerous vacuoles 

 and is surrounded by a zone of colourless transparent 

 ectoplasm. 12. Hyalodiscus. 



Nucleated organisms frequently with an external 

 mucous envelope, which adapts itself to the varying 

 movements of the individual. Endoplasm sometimes 

 much vacuolated ; pseudopodia sharply pointed. 



13. Nuclear in. 



Organism distinguished by the possession of a 

 chlorophyl corpuscle, which apparently represents the 

 nucleus. Forming colonies by tetraschistic division. 



14. 



Genus 11. VAMPYRELLA Cienkowski, 1865. 



a (pars) FRESENIUS in Abh. Senckenb. nat. Ges. II 

 (1856), p. 253. 



Vampyrella CIENKOWSKI in Arch. f. mikr, Anat. I (1865), 

 p. 205. 



Body actinophrys-like or polymorphous, plastic, and 

 capable of much variation ; possessing an obscure nu- 

 cleus or scattered nuclear substance, but destitute, in 

 most cases, of a contractile vesicle. Protoplasm granu- 

 lar, permeated with a reddish pigment, and containing 

 food-corpuscles and oil-like globules of variable size. 

 In certain species fusion of two or more amoeboid 

 individuals takes place immediately upon contact, form- 

 ing plasmodia. 



The reddish colour present in nearly all the Vampij- 

 rellde distinguishes this genus from other naked Gymno- 

 myxa. All are chlorophyl feeders. They differ from 

 the AmwT)dB in the character of their pseudopodia, 

 which, as a rule, are very fine and very mobile. The 

 habit of forming plasmodia by fusion of individuals is 

 particularly noticeable in one species of Vampyrella. 



