538 DESCBiPTiON OF [Pol^ffastrtca. 



its original characters, save that it is smaller, and instead of a smooth, 

 even surface, it has its tunic thrown into folds or undulations (fig. 19). 

 The spot from whence the embryo escaped, soon becomes im- 

 perceptible. 



The embryonic being developed from the Acineta-form stage of 

 Epistylis anastatica, is similar to the Trichoclina grandmella (Ehr.), and 

 probably is identical with it. Besides the Acineta condition of E. 

 nutans and E. anastatica, discovered by Stein, that of E. Grandis, 

 E. Berheriformis, E. Bo/rla, and of E. pUcatilis, has also been noticed, 

 less certainly, by the same observer. 



Epistylis galea. — Large, body conical, contractile by transverse folds; 

 mouth lateral and projecting ; pedicle thick, branched, and articu- 

 lated. Found upon Ceratophyllum. Size of body l-120th. 



E. anastatica fV. anastatica cratoegaria et ringens, M.) — Body oval, 

 without folds ; frontal margin dilated and projecting ; pedicle dicho- 

 tomous, smooth, or squamous, with foreign particles. Stomach-cells, 

 and a imited mouth and anus, are observable, but the alimentary canal 

 has not yet been seen. The granules of ova are white by reflected, 

 and yellowish by transmitted light. The clear vesicle is often to be 

 seen, but not its contraction. Growth of gemmae unknown ; self- 

 division longitudinal. Found upon Ceratophyllum, and also upon 

 small water Mollusca. Size l-280th. ; heighth of little tree l-140th. ; 

 ova l-12000th; range of development l-12,000th to l-280th. 



E. plicatilis (V. annularis et pyraria, M.) — Body conical and elon- 

 gated, contractile in folds ; fi'ontal margin dilated, ti'uncated, and 

 slightly projecting ; pedicle dichotomous, smooth, or, when foreign 

 bodies adhere, having a scaly appearance. It is often corymbose. 

 This species is white to the naked eye, but somewhat yellow beneath 

 the microscope ; it is very much like the preceding, is often found 

 with it, but is distinguished by being larger, by its ring-Kke folds 

 when contracted, and by the tasselled or tufted appearance of the 

 cluster. Size 1-2 80th. to 1-2 10th. 



E. grandis. — Body broadly campanulate, stalk decumbent, slender, 

 smooth ; the branches flexible and without articulations, but much 

 tufted. This is not only the largest fresh- water species of Epistylis, 

 but it also forms the greatest masses. Its proper coloiu" is a blueish 

 white, but it often appears of a yeUow or greenish hue, from the 



