602 



SYSTEMATIC HISTOEY OF THE IXFUSORIA. 



reservation ; for this envelope changes greatly in figure, in size, and structure, 

 according to the age and the different vital conditions under which the animal 

 lives. Stein met with one example in which a short pedicle attached the 

 Vaginlcola crijstaUma to the bottom of its sheath : indeed he does not admit 

 Cothuniia and Vaf/inicola to be generically distinct ; for the stems supporting 

 the sheath of the former are, he says, not generally longer than those belong- 

 ing to young Vaguucolce. In this point therefore he agrees with Dujardin. 



We have observed how close the resemblance is between Vorticella and 

 Vag'micola ; on the other hand, the points of separation are found in the 

 absence of a pedicle in the latter, which is fixed to the bottom of a sheath by 

 its posterior extremity, its anterior remaining free, and its whole body 

 capable of extension or retraction within the orifice of its case. Lastly, the 

 figure of the body is much more elongated in Vaginicola than in Vorticella. 



Vaginicola crystallina (Vorticella 

 stentorea et TricJiocla ingemta, M.) (xxvii. 

 10, 11). — Sheath crystalline, straight, 

 pitcher-shaped, slightly contracted near 

 the open end ; granules green. Length 

 of lorica 1-210". Upon Lemna, &c. 



V. tincta. — Sheath bro^niish-yellow, 

 urceolate, and nearly cylindrical; body 

 hyaline. Length of lorica 1-280". Upon 

 Zygnema decimum. 



V. decumhens. — Sheath brownish yel- 

 low, oval and compressed, decumbent on 

 one side, which is flattened ; the body 

 hyaline. Length of lorica 1-280". 



Stein corrects this description by 

 stating that the oval plano-convex sheath 

 has not a simple crescentic opening, 

 but is contracted so as to form a short 

 tubular neck, or projecting process, with 

 a transversely oval or reniform mouth. 

 It has consequently the closest resem- 

 blance to the sheath of Lagenophrys A?n~ 

 pidla ; but its orifice is rigid, and not con- 

 tractile as in the latter, and, further, 

 the animalcule is not afiixed to its mar- 

 gin, but to the bottom. On Lemna, 

 Zygnema, &c. 



V. valrata (Wright) (xxviii. 18, 19). 

 — Distinguished from V. crystallina by 

 the remarkable valve existing in its case 

 or sheath — which closes, in an inclined 

 position, over the animal when it retreats 

 to the bottom of its case ; by the body 

 being colourless, without the green glo- 

 bules seen in V. crystallina ; and by being 

 an inhabitant of sea-water instead of 

 fresh. Plentiful on zoophytes and sea- 

 weeds. 



V. vaginata. — Under the name Vorti- 

 cella vaginata, Midler described a Vagi- 

 nicola found in the Baltic, having a deli- 

 cate pedicle as long as the body, which 

 is supported by it, at the upper end of a 

 sheath six times longer than itself, into 

 the orifice of which it can with difficulty 

 enter. 



V. pedunculata (Eichwald). — Body 

 attached to the bottom of the sheath by 

 a short stem. This presumed species is 

 actually nothing more than a variet}^ of 

 F. crystallina, as Stein has shown. 



V. Amjndla. — Miiller described this as 

 larger than most animalcides, as dwelling 

 in a bottle-shaped sheath, as A'ery con- 

 tractile, grey, and soft, and as occupying 

 various positions witliin the case. Fomid 

 in the Baltic, and, by Mr. Brightwell, at 

 Lowestoft. Dr. Wright (J^din. Phil. Journ. 

 1858, p. 5) says it has a bilobed ciliated 

 organ, and so far resembles Lagotia. 



V. ovata (Duj.). — Body of a lengthened 

 ovoid figure, placed in an urceolate case. 

 Length of body 1-1000", of case 1-550". 

 Apparently distinct from V. crystallina. 

 On Zygnema in pond-water. 



V. ? (Brightwell) (xii. 70).— 



Body double, of a green colour. Pro- 

 bably undescribed. On duck-weed and 

 other small aquatic plants. It is doubt- 

 fid whether this being is other than a 

 Vaginicola in process of spontaneous 

 fission. 



V. grandis (Perty). — Sheath cylindri- 

 cal. Animals A\dth a circular ciliated 

 opening. Length of tube 1-108", of the 

 extended animal 1-84". Stein considers 

 this species a mere variety of V. cry- 

 stallina ; but besides differing from it in 

 size, it does so also in the figm'e of its 

 sheath, which is not rounded below, but 

 abruptly truncate, and not nan'ower 

 above, but rather wider. Animalcules 

 hyaline, often filled with sporozoids and 

 chlorophyll gTanules ; wheri contracted 

 it does not occupy more than a third of 

 the tubular sheath. Among water-plants. 

 Uncommon. 



The figure of this species presented by 

 Perty is very rude, convejdng not the 

 slightest conception of the details of 

 external structure or of internal organ- 

 ization. 



