620 



SYSTEMATIC HISTOET OF THE INFUSORIA. 



Confervie ; and xxv. 293, a specimen 

 iindergoing transverse self-division.) 

 Amongst Conferv^ae. 1-144" to 1-36". 



L. Cithara (Trichoda aurantia, M.). — 

 Triangular and compressed ; anteriorly 

 dilated and obliquely truncated, but 

 pointed at the posterior extremity. Co- 

 lour white. 1-430" to 1-210". 



L. Bursar ia. — Oblong ; anteriorly ob- 

 liquely truncated and depressed ; poste- 

 riorly hemispherical. The mouth is placed 

 near the centre of the ventral surface, at 

 the bottom of a deep funnel-like fossa 

 (vestibulum), the upper border of which 

 is longer, broader, rather concave, and 

 truncate, and constitutes the "upper 

 lip" of Ehrenberg. A long oesophagus 

 extends far into the interior from the 

 mouth. In bogs. 1-280". 



This, Focke and Stein show, is not a 

 species of Loxodes, but of Paramecium, 

 and therefore rightly named P. Bursaria 

 (which see, p. 635). It was this species 

 which was so elaborately examined by 

 Cohn, especially with regard to its repro- 

 duction. Young specimens are colourless; 

 but matiu'e beings have nimierous chlo- 

 rophyll-corpuscles diffused in their cor- 

 tical laminae . There are two round con- 

 tractile spaces, which by pressm-e assume 

 a stellate appearance similar to those of 

 P. Aurelia. The rotation of the contents 

 may be demonstrated in this species ; and 

 Cohn, Focke, and Stein have witnessed 

 its reproduction by a living germ or em- 

 bryo. In figure it is very like Chilodon 

 Cucidlulus, but has the oral fossa (vesti- 

 bule) and cilia of Paramecium, 



L. plicattis. — Elliptical, depressed, 

 convex on the back, and slightly plicated; 

 the lip uncinate. On Confervse. 1-430". 



The species of Loxodes mentioned by 

 Dujardin are L. Cucullidus = Chilodon 

 Cucullus (Ehr.) ; and L. Cucullio = (?) 

 Kolpoda Cucullio (M.), placed by Ehren- 

 berg among the Kolpodea. 



L. reticulatus. — Oval ; more slender, 

 sinuous, and flexible anteriorly ; surface 

 granular. In long-kept marsh-water. 



This species is, in Stein's opinion, a 

 mere accidental variety of ChilodonCucul- 

 lulus, determined by the bulk of food 

 received. 



L. marinus. — Depressed, oval, almost 

 renifoim; with internal tine granules, 

 and a row of puncta near both the ante- 

 rior and posterior margins. 1-350". In 

 salt water. 



L. dentatus. — Similar to L. Cucullulus, 

 but ha\'ing a bundle of bristles about the 

 mouth, as in Giilodon, from which it 

 differs by the lorica (cuirass) and by the 

 absence of cilia on the surface. 



The distinction of this species and L. 

 Cucullulus as independent, Stein rightly 

 criticizes as an error on the part of Du- 

 jardin, and shows {Infus. p. 131) that both 

 of them are only accidental varieties of 

 Chilodon Cucullulus, — Loxodes Cucullulus 

 being nothing more than small specimens 

 in which the oesophagus is indistict, and 

 L. detitatus examples in which this organ 

 is very evident. 



L. hrevis (Perty). — Short, rounded, 

 with a hyaline proboscis. 1-500". Bern, 

 in rainwater-ponds. 



Genus BURSARIA (XXIV. 294-296).— Surface ciHated throughout; an- 

 terior part convex ; mouth not terminal, fringed with stronger cilia, though 

 simple, toothless, and devoid of tremulous flap. The cilia are distinctly seen 

 in coloured water, and are generally disposed in rows; those around the 

 mouth are longer than the others. The nutritive system (says Ehrenberg) 

 consists of an alimentary canal, cui'ved forwards ; it is fui'iiished with diges- 

 tive cells resembling little purses, which are attached to it by short stalks. 

 The mouth is large, situated, as in Leucophrys, obliquely at the anterior ex- 

 tremity, so that a brow, as it were, either projects over it or else forms the 

 end. The contractile vesicle is sometimes doubled ; the nucleus oval or 

 ovoid. The anus is placed at the posterior extremity. SeLf-di\dsion, longi- 

 tudinal or transverse, has been observed in five species. 



Dujardin has the following remarks on this genus : — " Ehrenberg, whilst 

 admitting a genus Bursaria, separates from it several true species, and 

 places some of them in his genus Leucophrys, others in his family Kolpodea ; 

 whilst the closely allied genera Kondylostoma and Playiotoma are confounded 

 with other families — the former with O.vytriclia, the latter with Paramecium. 

 Moreover, the obliquity of the mouth in Bursaria is not a sufficient distinc- 

 tion between that genus and Leucophrys ; and, whilst assigning a large mouth 



