GENUS VASICOLASTROMBIDINOPSIS. 613 



at will of severing such attachment, and swimming freely in the water. The pedicle 

 under such conditions is entirely retracted, and the body, as shown in the figure 

 last quoted, presents an evenly ovate contour. Multiplication by transverse fission 

 was observed, the process being preceded, as in Tintinnus urnula^ by the develop- 

 ment of a new and smaller adoral fascicle of cilia toward the posterior region of the 

 lateral border. Since Stein has, as above mentioned, recorded the presence of fine 

 hair-like setae towards the anterior region of Tintinniditim fluviatilis, it would seem 

 to be by no means improbable that the present form may eventually prove to be 

 but a synonym of that type. 



GENUS III. VASICOLA, Tatem. 



Animalcules more or less ovate, elastic and changeable in form, inhabit- 

 ing adherent, transparent loricae, within the cavities of which they remain 

 freely suspended, and from out of which they emerge at will ; oral aperture 

 at the anterior extremity, surrounded by a circlet of long cirrate cilia ; anal 

 aperture postero-terminal ; cilia of the general cuticular surface equal in 

 size, evenly distributed. 



Vasicola ciliata, Tatem. PL. XXX. FIGS. 27 AND 28. 



Lorica hyaline, erect, shortly flask-shaped, about twice as high as broad, 

 truncate posteriorly, slightly widest centrally, narrowing anteriorly into a 

 short, wide neck, its surface finely corrugate transversely ; animalcule ovate 

 or pyriform, filling the greater portion of the cavity of the lorica, the oral 

 orifice in extension usually level with the front border of the lorica, the 

 longer oral cilia springing from a more prominent raised lip or peristome ; 

 cuticular cilia fine, evenly distributed ; parenchyma usually enclosing 

 numerous light, claret-coloured food-globules. Length of body 1-180", 

 height of lorica 1-150". 



HAB. Pond water with decaying animal and vegetable matter. 



No reference is made by Mr. Tatem in his description of this type * to the 

 presence of either an endoplast or contractile vesicle, the exact form and posi- 

 tion of the oral aperture being left in similar uncertainty. While under examination 

 the animalcules were found to be exceedingly impatient of restraint, usually issuing 

 from their loricae, and swimming freely in the water soon after their transfer to the 

 stage of the microscope. The ingestion of food-particles, including chiefly vibriones, 

 monads, and minute fragments of decaying vegetation, was abundantly observed, 

 as also on repeated occasions the increase of the animalcules within their loricae by 

 transverse fission. The brilliant colour of the food-globules, recorded in the fore- 

 going diagnosis, is not conspicuous until after their retention for some little time 

 within the substance of the parenchyma, and is, as suggested by Mr. Tatem, in 

 all probability attributable to the chemical action of the assimilative process. A 

 somewhat analogous coloration of the incepted food-particles has been already 

 observed to take place in relationship with certain species of the genus Nassula. 



GENUS IV. STROMBIDINOPSIS, S. K. 



(Strombidium ; opsis, like.) 



Animalcules free-swimming, illoricate, ovate or pyriform, persistent in 

 shape ; peristomal cilia enclosing the entire frontal border, consisting of a 

 spiral wreath of one or more turns of long, powerful, cirrose cilia ; the whole 

 * ' Monthly Microscopical Journal,' vol. i. p. 117, 1869. 



