as Infusoria flagellata. 191 



to detect, even with a power of eight hundi-ed diameters, not 

 only because it is seldom at rest, but on account of its exces- 

 sive delicacy ; yet when it does stop its vibrations, its charac- 

 ter and proportions can be unequivocally demonstrated under 

 the proper circumstances of illumination and adjustment. It 

 is about twice as long as the body, and has a decided although 

 not rapid taper at its distal termination. 



The mouth remains yet to be discovered. There can be no 

 doubt, however, that it is an aperture of no very small extent, 

 or at least that it is capable of considerable distention, inas- 

 much as we find quite large angular particles within the body. 

 That it is terminal rather than lateral, is probable from the 

 similar position of this organ in the not very distantly allied 

 genus Codosiga (§ 6). 



The two contractile vesicles (cy, cv) are situated midway be- 

 tween the front and hind ends of the body, and at two nearly 

 opposite points. They are of moderate size, yet not so large 

 as those of Codosiga (§ 6), which they resemtale, but exhibit a 

 much feebler action than the latter. 



The calyx (c^ c c^), or carapace so called, has an ovate- 

 campanulate outline, but is divided by a constriction into two 

 regions. One of these, the basal (c^) or posterior third, is about 

 one-half as wide as the remaining two-thirds (c), and possesses 

 an ovate-obconical form, which tapers abruptly into the pedicel 

 {pd). The anterior two-thirds (c) arises from the sharp con- 

 striction with a strong swell or bulging, and then, narrowing 

 a little, terminates with a truncate aperture (c^) ; so that on the 

 whole this portion may be compared, in shape and proportions, 

 to a claret-glass. This region is peculiar, moreover, in being 

 longitudinally banded or sulcated by about twenty furrows, 

 which terminate at the rim in as many notches, that alternate 

 with a like number of distinct scallops. Of these two regions, 

 the basal one is quite distinct, although perfectly hyaline ; but 

 the banded part is much fainter, and requires a careful adjust- 

 ment of the light in order to bring it out clearly. The pedicel 

 {pd) is moderately slender, colourless, at least as long as the 

 calyx, and of a uniform thickness from base to top. 



§ 6. Codosiga, nov. gen.* 



Codosiga pidcherrima.) nov. sp. PI. V. figs. 7-27. 



This infusorian is as eminently a compound Flagellifer as 

 Anthopliysa (§11), and, although not a heteronematous form 

 (like the latter), it bears a very striking general resemblance to 

 it, as one may see by comparing figs. 8 and 47 with each other. 



* KcoScoi/, a bell ; o-iyao), to be silent. 



14* 



