130 H. JAMES-CLARK ON THE ANATOMY, ETC., OF TRICHODINA. 



of the feces. The velum (f,f Y ) is only partially expanded. From the position of the animal the basal cilia (^r) 

 are dxposed at full length. The hooks and radii of the adherent apparatus (//) are but dimly seen through the cor- 

 rugated walls of the. body. From its peculiar position in this view the vestibule is seen through the open mouth (»i). 

 The moniliform nucleus (n) is seen in the extreme distance, its right (n) and left ends are foreshortened, and appear 

 as two very conspicuous, dark yellow, oval spots, easily seen even with a low magnifying power. 650 diism. 



Fig. 13. An end view of the anterior face, looking directly into the cupuliform disc (c 3 ), and through its walls 

 upon the various organs. The ventral region corresponds to the lower side of the figure. The anus (a) appears 

 as a faint slit on the right border of the vestibule (v). The vibratory crown (b) commences abruptly on the right 

 (i 1 ) side, and appears clearly defined as a spiral just within the peristome (d l ), and equally well marked where it 

 forms a curve (J-) at the bottom of the vestibule (»). It is quite evident, from this view, that the disc (c") is insep- 

 arable from the peristome (d 1 ), except by the slight, narrow furrow from which the cilia arise. The peristome is 

 designated by a double border (d 1 ) (the outer and inner walls) along the spiral course of the vibratory row (b,b l ), 

 but at the mouth (at d) of the vestibule (i>) it loses that character, and gradually shades off (at d 4 ) into 

 the surrounding surface. The lumen of the vibrating row of cilia — the vestibular lash (e) falsely so-called — 

 appears distinct from this point of view. The contractile vesicle (cv) is in full diastole. Its distance from the ventral 

 side of the body is rendered apparently unusual by the expanse of the disc (c 3 ). The circle (A, /<') of hooks and the 

 radii are in the extreme distance ; the hooks partially overlaid by the knotted nucleus (n, ti*) and the oesophagus 

 (o). The oesophagus (o) is in a scarcely expanded state, having but a few granules within it. The principal 

 feature is its decidedly marked curve in the opposite direction from that of the vestibule (v). The " digestive 

 vacuoles " (q, q) lie nearest the observer. 650 diam. 



Fig. 14. A dorsal view of the body. The keotropic leaning of the cilia (b) of the vibratory crown is more 

 decidedly marked than in the previous figures. The bottom (c) and flank (c 1 ) of the cup-shaped disc are seen 

 in strict profile through the corrugations (r) and furrows of the outer (/>) and inner (p 1 ) walls. The contractile 

 vesicle (cv) is in the extreme distance, at its full diastole. The peristome (d l ) appears as a distinct ridge just 

 exterior to the vibratory crown. The velum (f) is in a semi-expanded state. The cilia (r/) of the ba.-al crown 

 are stretched to their full length. The circle (//) of hooks is scarcely recognizable as such in an edge view like 

 this. The nucleus («) lies next the observer. The outer wall (p), as in previous figures, bristles with numerous 

 immobile, short cilia. The inner wall (p l ) is dotted everywhere by a minute scattered granulation. The longi- 

 tudinal ridges (r) of the body bear a singular resemblance to muscles. 650 diam. 



Fig. 15. A diagramic enlargement of the edge of the disc, principally to show how the cilia (b) arise from the 

 furrow (W), and also the relation of the peristome (d 1 ) to the furrow. The outer (p) and inner (p 1 ) walls are 

 represented in their relative proportions. 



Fig. 16. A portion of the adherent apparatus, from a dead animal, to show the wrinkling of the striated mem- 

 brane (I 1 ) and the overlapped, apparently forked, coarser stria- (Z 2 ). The latter are seen through the thickness of 

 the membrane, the finer stria} being omitted. The hooks (/() and radii (i) lie on the side next the eye. 

 950 diam. 



Fig. 17. A basal view of the adherent apparatus, velum, and a part of the posterior row of cilia. The hooks 

 (h) with their crests (£) lie nearest the observer, and partially covering the striated membrane (I 1 to I s ). The 

 radii (t, f) with their webs (i 3 ) fill up the central area. The posterior face of the striated membrane with its finer 

 striae is shown from Z 4 to Z 5 ; and the anterior face of the same, as seen through its thickness, with its coarser strice 

 (Z 2 ), between I 1 and IK The distal edge (Z 1 ) is crenated and thickened. The proximal edge (Z 3 ) runs along the bases 

 of the hooks. The velum (f 1 ,/ 1 ) is attached by its proximal edge (/ 2 ) close to the distal margin (Z 1 , Z 4 , Z 5 ) of the 

 striated membrane, and almost the same with, but just anterior to, the line of attachment of the cilia (g, g) of the 

 basal crown. Between Z 5 and/- the stria? of the membrane are omitted. 950 diam. 



Fig. 18. Two of the hooks and their corresponding radii, from the adherent apparatus of a dead specimen. The 

 hook (/(), its horizontal limb (A 8 ), the spur (A' 2 ), and the crest (k) apparently form one solid piece. The r<idius (i) 

 and the nail-shaped, transverse piece (i 1 , r) are united at the angle by a triangular web (»*). The mechanical con- 

 trivance for the sliding of these pieces upon and between each other is too obvious to need any comment. 

 2400 diam. 



Cambridge, Mass., October, 1865. 



Published February, 18G6. 



