Cr-yptomonadina.'] infusorial animalcules. 147 



double filiform proboscis is seen. Sell'-clivision has not been observed 

 in any of the species, which are all of a green coloui'. 



Ckxptoglena conica. — Foiin conical, anteriorly dilated and trun- 

 cated, and furnished with two filiform proboscides, half the length of the 

 body; posterior acutely attenuated. Colour a blueish green. Group 29 

 is a magnified representation of three creatures. They are found in 

 great numbers in butts of river water, in company with the Crypto- 

 nionas glauca, from which they are readily distingidshed by their 

 foi-m, larger size, and red eye. They move briskly in the direction 

 of the longitudinal axis of their bodies, but when obstructed, they 

 spring or leap out of their coui'se. Size 1- 1100th. 



C. pigra. — Form oval, approaching to globular, and emarginate 

 anteriorly ; colour a beautiful green ; movement slow. Foimd in 

 water, when covered with ice. Size 1 -3000th. 



C. cmrulescens. — Form depressed, elliptical and emarginate ante- 

 riorly ; colour blueish-gi-een ; motion qiuck. Found amongst con- 

 fei-vae. Size 1 -6000th 



Genus Teachelomonas. The Monads ivith the trunk. — This genus 

 comprehends those loricated animalcules of the family Cryptomo- 

 nadina which are possessed of the visual organ, and of a closed box- 

 like elongated or spherical lorica, but without the projecting neck. 

 They are fui-nished with a single long filifonn proboscis or seta, for 

 the purposes heretofore described, and in two species, T. nigricans, 

 and T. volvocina, very minute transparent vesicles have been dis- 

 cerned, which are most probably theii- digestive sacs. In the species 

 T. cylind/rica, egg-like granules are visible. Two species are green, 

 and one blackish-brown. It is most pi'obable that those highly in- 

 teresting animalcules which enter so abundantly into the silicified 

 substances in certain chalk formations belongs to this genus. 



T. nigricans. — Form oval, approaching to globular ; colour rarely 

 green, mostly of a reddish or blackish-brown. Eye brown. Size 

 l-1700th. 



T. volvocina. — Form sperical ; colour mostly green, sometimes of a 

 brownish hue, but easily distinguished by a red ring on the cii'cum- 

 ference of the body ; vesicles may be observed internally, which are 

 most probably the digestive sacs, between which a very fine granulated 



