HISTOLOGY OF THE LAND-PLAN ARIANS OF CEYLON. 
153 
transverse to the long axis of the body, at a spot just anterior to the mouth. 
Drawn with the camera lucida. 
The section contrasts strongly with those displayed in figs. 5, 6, & 7, in being 
lengthened out from side to side, and having its superior and inferior surfaces 
irregularly parallel, owing to the flattened-out form of the Planarian from 
which it was prepared. The central digestive cavity D, with its diverticula D', 
is more irregular in outline than in Bipalium and Rhynchodemus. The dark 
glandular masses (T, T) are seen scattered over the section, but in this par- 
ticular one are exposed in greater abundance on the left side. The main 
trunks of the water-vascular system (W, W) are here, as in Bipalium and 
Rhynchodemus, rendered conspicuous by their being but slightly tinted with 
carmine. The oviducts are situate just above them, as also is the case in 
Bipalium and Rhynchodemus. A circular muscular coat succeeds the epi- 
thelial layer ; and closely opposed to this are the longitudinal muscles of the 
body, in this animal not divisible into two systems, as in Bipalium and Rhyn- 
chodemus. The stout vertical fibres which run from one surface of the body 
correspond to the internal circular and radiating muscular fibres of the two 
Land-Planarians already figured. The small darkly stained masses partly 
internal to and partly mixed up with the longitudinal muscular fibres consist 
of urticating organs and small glandular masses, and some of them represent 
longitudinal muscular fibres exceptionally darkly stained. 
D. Central gastro-intestinal canal. 
D'. Lateral diverticula given off from central canal, D. 
E. Epidermis. 
E. C. M. External circular muscular layer. 
L. M. Longitudinal muscular layer. 
Y. M. Vertical muscles. 
OD. Oviducts. 
T. Testis. 
W. Water-vascular trunks. 
X. Glandular masses. 
Fig. 9. Three rod-like bodies from Bipalium Diana as they appear in sections from spirit- 
specimens, stained with carmine and mounted in dammar varnish. 
Fig. 10. Epidermic structures from similar preparations. 
A. Elongated irregularly shaped body often seen in the epidermis, deeply 
stained with carmine, and frequently in continuity with the glandular 
masses (G) represented in fig. 1, Plate XI. ; probably masses of mucus 
hardened by alcohol in the act of their ejection from these glands. 
B. One of the gland-cells (G. C.), fig. 4, Plate XI. 
Fig. 11. From similar preparations, two parent cells of rod-like bodies ; on the right 
a cell in transverse section, showing three chambers. Fig. 12. Fragments of 
similar cells. 
MDCCCLXXIV. 
X 
