62S 



SYSTEMATIC HISTORY OF THE ITI^FUSORIA. 



greater contractile power, this really is questionable, and, if true, is not a 

 proper generic character. 



Panopitrys C7in/salis (xxvi. 33). — 

 Ovoid, oblong, depressed, mouth accom- 

 panied by an enlargement, and placed 

 near the front exti-emity. 1-145" In 

 sea-\vater. 



P. rubra (?). — Eeniform, covered with 

 fine cilia, and provided with a lateral 

 mouth near the front extremity. 1-370" 

 to 1-325". In sea- water. Only pro- 

 visionally named. 



V.farcta. — Ovoid, oblong, filled with 

 particles of a green reddish-yellow hue, 

 or of various mingled colours ; mouth 

 lateral, placed between the centre and the 

 anterior third of the body. Its outline 

 is very changeable, its movements rapid. 

 The colour is seldom green. 1-145" to 

 1-95". In marsh- water among plants. 

 I think it is the animalcule described 

 under three names by Ehrenberg, viz. 

 Bursaria vernalis, B. Icucas, a,nd B.Jlava, 

 and is probably the same as Leucophra 

 virescens of MiiUer. 



Although Perty acquiesces in the be- 

 lief that the yellow-coloured specimens 

 of this species are the Bursaria Jiava 

 (Ehr.), yet he thinks Dujardin wrong 

 in claiming B. leucas and B. vernalis as 

 varieties. 



P. conspicua (Perty). — Large ; cylin- 

 drical, scarcely smaller behind than in 

 fi'ont ; mouth round. Coloured by food 

 dark green. Swims, revolving at the 

 same time v^-ith moderate speed. 1-95". 

 In peaty ponds \ni\\ Lemnpe. 



P. sordida (Perty). — Cylindrical, more 

 or less elongated ; colour dark, earthy- 

 brown. Mouth small. Cilia covering the 

 body, fine. The position of the internal 

 molecules varies even during examina- 

 tion, and the figure with them. 1-180" 

 to 1-96". Among Charae. 



P. (jriseola (Perty) (xxviii. 31). — 

 Broad, distended ; grey, but transparent, 

 with a tine reticulate appearance ; mar- 

 ginal concentric stride. Sometimes occu- 

 pied with chlorophyll-granules, when 



it much resembles OijhrijogJena griseo- 

 virens. The mouth appears like an 

 elliptic fold in a shallow fossa in the 

 anterior half. It swims and turns on 

 itself with much activitv. Transverse 

 fission observed. 1-300" to 1-108". 

 Among deca^-ing plants. 



P. zonalis (Perty). — Elongated, ovate- 

 cylindrical ; h^-aline, with a central zone 

 of dark molecules. Extremities equally 

 wide, and rounded. Fissure of the mouth 

 beset with stronger cilia. Movements 

 rather sluggish. Body ciliated through- 

 out. 1-168". 



This scarcely seems a true Panophrys ; 

 for the oral cilia are said to be larger 

 than those on the body, contrary to 

 Dujardin's characters of the genus. 

 Moreover its chief peculiarity, viz. the 

 zone of darker granules, is an insuificient 

 specific feature ; and when we are told 

 by Perty that he has only once seen a 

 small specimen, this supposed species has 

 few claims to notice. 



P. paramecioides (Perty). — Cylindri- 

 cal, slightly curved, its posterior end 

 somewhat thicker than the anterior; 

 colourless ; rows of cilia very numerous 

 and fine. Its molecular structure re- 

 sembles that of Paramecium Aurelia. 

 Movements energetic, twisting. The 

 mouth is placed in a shallow fossa on 

 one side of the body. 1-108". An un- 

 common form in Switzerland. 



There is scarcely anything in the above 

 description which is not compatible with 

 the belief that the animalcule in ques- 

 tion is either a Bursaria or a Parainecium. 

 Moreover, reference to Perty's figm-es 

 lends no aid to the determination of tlie 

 question ; and we must confess our in- 

 ability to find, in his illustrations of the 

 gemisPanophri/s, any sufficiently detailed 

 particulars to enable us to distinguish 

 either of the species named as members 

 of it from probable representatives of 

 allied genera. 



Genus BLEPHARISMA (Perty) (XXYIII. 33, 34).— Body compressed, 

 lancet-shaped, ^vith a pointed posterior extremity, whence a deep fossa ex- 

 tends as far as the middle, fringed with longer and straighter cilia than cover 

 the rest of the body. The internal molecules are disposed in longitudinal 

 rows, over which the very fine and inconspicuous cilia are arranged. 



Blephahisma hyalinum (xx^t:ii. 33, 

 34). — Colourless, except when occupied 

 by swallowed chlorophyll-particles. Body 

 thin, flexible, and changeable in form; 



older specimens are broader. Movements 



varied and tolerably rapid. Sometimes 



a few large and non-vibratile filaments 



i appear to issue from the oral fossa. 



