GENUS CH^TOSPIRA. 6oi 



peristomal lobes ; the lorica most nearly resembles that of F. elegans, but the margin 

 is even and not everted, and there are no internal valves. The colour and con- 

 sistence of this structure apparently agree with those of various species of the genera 

 Cothiirnia and Vaginicola, and in the absence of the animalcule might be mistaken 

 for the lorica of Vag'uikola {Platycola) loiigiciUis. The species oi Lagotia {FoUiculina) 

 referred to though not described by Mr. Barrett* as occurring in company with 

 Stentor Baretfi, in the river Thames, near Moulsford, is probably identical with the 

 present type. 



Genus III. CH^TOSPIRA, Lachmann. 



Animalcules highly elastic and contractile, inhabiting an attached 

 mucilaginous or horny sheath or lorica, to the inner wall of which they are 

 not, however, organically united ; peristome represented by a slender, ligulate 

 extension of the anterior region, which, when the animalcule is expanded, 

 projects beyond the aperture of the lorica and is twisted into a more or less 

 extensive Iseotropous or left-ascending spire ; a hyaline membraniform 

 expansion extending laterally along the broad portion of the ligulate 

 peristome and forming with it a gutter-like channel, which conducts to the 

 oral aperture ; this adoral groove continued backwards into the sub- 

 stance of the parenchyma as a narrow tubular pharynx ; a row of large, 

 prominent, cirrate adoral cilia bordering the entire length of one side of 

 the ligulate peristome, commencing at the apical extremity and terminating 

 in the vicinity of the mouth ; cilia of the general cuticular surface fine, 

 distributed in even longitudinal rows ; supplementary, delicate, hair-like 

 setae sometimes projecting in an irregular manner from the surface of the 

 integument. Inhabiting fresh and salt water. 



Lachmann, when instituting the generic title of Ch(Etospira,\ hazarded the 

 opinion that the animalcule to which he gave that name might possibly be identical 

 with the, at that time, very imperfectly described Stichotricha secunda of Perty. 

 Stein, who has since met with this last-named type, and figured and described 

 it in his monograph of the Hypotricha, adopts this view, and has no hesitation in 

 pronouncing the two to be the same. The present author is inclined, however, to 

 dissent from this decision, having observed an animalcule which, while corresponding 

 in all important points with Lachmann's species, is altogether distinct from the one 

 figured by Stein, and referred correctly, so far as it is possible to decide, to Perty's 

 Siichotricha. This latter form, as made known by the more recent investigations of 

 Stein, and described further on in this volume is, as first premised by Perty, an 

 unmistakable representative of the Hypotrichous family of the Oxytrichidce, sharing 

 with the more ordinary members of that group the characteristic ciliation, which is 

 restricted to the ventral surface of the body, and there limited, in addition to the 

 adoral fringe, to a few widely separated rows of short, non-vibratile, ventral and 

 marginal, setose cilia. In C/icefospira, on the other hand, the character and distri- 

 bution of the cuticular cilia is entirely diverse, taking the form of fine vibratile cilia, 

 which are distributed in close parallel rows throughout the surface of the integument 

 as in an ordinary Holotrichous animalcule, the anterior fringe of powerful adoral 

 cirri necessitating, however, its reference to the higher order of the Heterotricha. 

 Among these it is evident that its correct position is not very remote from the 

 genus Folliculina, and with certain representatives of which, such as F. prodiicta or 

 F. hinmdo — premising one of the ligulate peristome-lobes to be suppressed and 

 the remaining one to be twisted in a spiral manner — it might be appropriately 



* 'Monthly Microscopical Journal,' April 1S70. f Muller's 'Archives,' p. 362, 1S56. 



