590 



SYSTEMATIC HISTORY OF THE INFUSORIA. 



Epistylis Galea. — Large, conical, 

 contractile by transverse folds; mouth 

 lateral and ]3rojecting; pedicle thick, 

 branched, and articulated. Upon Cera- 

 tophijUum. 1-120". 



E. anastatica ( V. anastatica, craicsc/aria 

 et ringens, M.). — Oval, without folds; 

 frontal margin dilated and projecting; 

 pedicle dichotomous, smooth — or squa- 

 mous with foreign particles. The gra- 

 nules are white by reflected, and yel- 

 lowish by transmitted light: the clear 

 vesicle is often to be seen, but not its 

 contraction; growth of gemmae un- 

 known ; self-division longitudinal. 

 Upon Ceratophi/llum and small aquatic 

 Mollusca and Entomostraca. 1-280"; 

 height of little tree 1-140". 



'' JE. anastatica,'''' says Stein, " diiFers 

 from E. I)iffitalis,w]uch. it very closely re- 

 sembles, by the form of its body, which is 

 always funnel-shaped and campanulate, 

 like that of E. pUcatilis, only less elon- 

 gated, and by the branches of its stem 

 being outspread in a fan-like manner 

 and acquiring a nearly equal height, or 

 an umbellate condition." He adds, "■ The 

 three species most nearly allied, viz. E. 

 anastatica, E. pUcatilis, and E. Digitalis, 

 have, when studied at different ages, few 

 points of separation, except that furnished 

 by their habitats, — E. pUcatilis living 

 upon the shells of Mollusca; E. anas- 

 tatica upon the roots of Lemna ; and E. 

 Digitalis upon Cgclops quadricornisy 



E. pUcatilis ( V. annularis et pgraria, 

 M.). — Conical and elongated, contractile 

 in annular folds ; frontal margin dilated, 

 trimcated, and slightly projecting; 

 pedicle dichotomous, often corpnbose, 

 smooth, or, when foreign bodies adhere, 

 of a scaly appearance. This species is 

 white to the naked eye, but somewhat 

 yeUow beneath the microscope ; it is 

 very much like the preceding, is often 

 found with it, but is distinguished by 

 being larger, by its ring-like folds when 

 contracted, and by the tasselled or tufted 

 appearance of the cluster. 1-280" to 

 1-210". 



The stem, says Stein, is solid and 

 longitudinally striped. The nucleus is 

 reniform, and the contractile vesicle lies 

 within the substance of the large rotary 

 organ. In old stems transverse lines or 

 joints appear, at a distance from one 

 another. The largest examples Stein 

 met %vith were 1-168" in length. 



E. grandis. — Broadly campanulate, 

 stalk decumbent, slender, smooth; the 

 branches flexible and without articula- 

 tions, but much tufted. This is not onlv 



the largest freshwater species of Epi- 

 stglis, but it also forms the greatest 

 masses. Its proper colour is a bluish 

 white ; but it often appears of a yellow or 

 greenish hue, from the colour of its food. 

 Upon Ceratophgllum and Ngmphcea, 

 often like a bluish- white slime, easily 

 broken up. In masses several feet long, 

 and two to three inches thick. 1-140" to 

 1-120". 



E. Jlavicans ( V. acinosa et hellis, M.). 

 — Large, broadly campanulate, and of 

 a yellow colour; pedicle smooth, its 

 branches coarctate. The branches are 

 dilated at the axillae. In this species the 

 alimentary canal is very evident. Size 

 (stretched out) 1-190";' tree 1-9" high. 



Although Stein represents the stem 

 in Epistglis to be, as a rule, solid, yet, in 

 a passing notice (p. 72) of E. JiavicanSj 

 he remarks that the pedicle evidently 

 had a hollow central canal. 



E. leucoa ( Volvox SphiBnda, M.). — 

 Large, broadly campanulate ; pedicle 

 erect, smooth, and articulated; the 

 branches capitate or collected in a head. 

 These animalcules are convex anteriorly, 

 have distinct colourless granules, a sim- 

 ple ^vl'eath of cilia, and a round mouth on 

 the margin. The nucleus is bent in the 

 form of the letter S. ^ 1-120" ;_ tree 1-24". 



E. Digitalis ( F. Digitalis, ringens et m- 

 clinans, M.). — Small, cylindrical, campa- 

 nulate; stem dichotomous, and finely 

 annulated. This weU-marked fonn in- 

 fests the Cyclops quadricornis, which it 

 sometimes completely covers. In the 

 beautifid little tree this species fomis by 

 its branching", the Notommata petroniyzon 

 nestles just like a bird in a bush, and 

 fastens its eggs to its branches. Coloured 

 food is readily taken. 1-430" ; tree 1-20". 



The figure is more like that of the 

 flower of the foxglove (^Digitalis), as the 

 name implies, than bell-shaped ; for the 

 peristom is very little everted, and its 

 diameter not greater than the middle of 

 the body. The rotary organ protrudes 

 some distance, and lies very obliquelv. 

 The nucleus is band-like, and cm-ved in 

 a semicircle. The annulation of the 

 stem could not be seen by Stein, except, 

 as in very many Epistgl ides, near the jimc- 

 tion or 'bifm-cation of the branches, and 

 occasionally in very old specimens : in 

 these last it often has a rusty colour. 



E. (?) mdans {Opercularia nutans, 

 Stein). — Ovate, attenuated at both 

 ends ; mouth two-lipped and prominent. 

 The pedicle annulated (xxvn. 16, 22, 

 23). "This animalcule," says Ehren- 

 berg, "can push forth a bladder between 



