422 Prof. H. James-Clark on the Anatomy and 
cilia-crown; h, the hooks of the adherent organ; h!, the circle formed by 
the bases of the hooks; A’, the spur of 4; A’, the horizontal limb of the 
hook ; 7, the radii; 7, the “nail-shaped piece ;” 7, the head of the same; 
i, the “ faint membrane”’ or web of the T-shaped radii; 7*, the pomt of 
the nail-shaped piece; k, the crest of the hooks; /, the profile of the 
“striated membrane ;”’ /', the distal edge of the last; /?, the coarser strize 
of the same, on its front face; /°, the proximal edge of the same; /*, 1°, a 
portion of the posterior face of the striated membrane, showing the finer 
strie ; m, the mouth of the vestibule; , the nucleus, or reproductive or- 
gan; n', the left end of the nucleus; 0, the cesophagus; o', the bottom of 
the same ; p, the outer, and p’, the inner walls of the body; q, digestive 
vacuole ; 7, longitudinal ridges on the surface of the body; s, the general 
digestive cavity ; v, the vestibule. 
All the figures represent the whole or portions of Trichodina pedicu- 
lus, Ehr. 
Puate VIII. 
Fig. 1. An individual in the fullest degree of expansion. This is the most 
common form of the animal. 200 diameters. 
Fig. 2. Another, less frequent form of a fully expanded individual. 200 diam. 
- Fig. 3. An attitude occasionally, but briefly, assumed by healthy specimens. 
The body is simply shortened, but without changing or reversing 
the relative position of the organs. 200 diam. 
Figs. 4 & 5. Shapes assumed when swimming, different from those already 
described. 200 diam. 
Fig. 6. An individual with the edge of the cup-shaped front (disk) rolled 
back so as to expose the bottom of the cup. 200 diam. 
Fig. 7. A partially retracted individual, with one side of the cupuliform 
front rolled back. 200 diam. 
Fig. 8. A profile view of the left side, showing the following parts : viz., 
the left flank (c*) of the front partially reverted, and the right 
flank im the distance bearmg the vibratory crown (b); the 
bottom (c) of the cupuliform disk in the distance, and its flank 
in profile (c'); the contractile vesicle (cv), at full diastole, lying 
near the ventral side of the body ; the peristome (d) opposite the 
mouth (m), i.e. where the cilia—of the vibratory crown (b)— 
leave it and enter the vestibule (v), also the profile (d+) of the 
same at the dorsal margin; the falsely called vestibular lash 
(bristle) (e) apparently attached near the dorso-anterior side of 
the vestibule; the velum in profile (f), and nearer the observer 
(at f!) overhanging the base of the posterior row of cilia (9) ; 
the ring (h!) of hooks of the adherent organ foreshortened, 
i. e. seen strictly edgewise ; the left half (m') of the nucleus most 
conspicuous next the back, where its length is foreshortened ; 
the cesophagus (0 to o'), partially filled by a nutritive pellet in the 
process of formation and rapidly revolved by the action of the 
vibratile cilia; the filmy, colourless outer wall (p) projecting very 
conspicuously in profile, and in marked contrast with the bright 
amber-coloured mner one (p'); the general digestive cavity, oc- 
cupied by numerous “digestive vacuoles”’ (q), nutritive pellets, 
and smaller alimentary concretions; the wide aperture (m) of the 
vestibule (v), and the latter obliquely traversed by the posterior 
termination of the spiral vibratory crown. 850 diam. 
Fig. 9. A transversely sectional view of the mid region of the body, to 
show its irregular contour and the corrugations of the outer ( p) 
and inner (p') walls. 850 diam. 
