HISTOLOGY OF THE LAND-PLANARIANS OF CEYLON. 
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This longitudinal section allows the basement membrane to be clearly dis- 
tinguished from the external circular muscular layer. In transverse sections 
they nearly always appear fused. 
Fig. 10. Ideal section of the eye of Leptoplana tremellaris. 
C. Cornea. 
L. Lens made up of rod-like bodies with rounded nucleus. 
Ch. Choroid. 
R. Retina. 
Y. Highly refracting transparent substance. 
Fig. 11. The same preparation as the one figured Plate XI Y. fig. 8, seen when focused, 
so as to render visible a deeper stratum. The mouths of the ciliated pits (A) 
are seen to be oval in form, and to have a very distinct lining, which is dotted 
with cilia. 
Fig. 12. Papillae from the anterior margin of the head of Bipalium Proserpina, from 
a section similar to that from which the preceding figure was drawn. The 
papillae are of much the same form as those of Bipalium Diana, but the 
mouths of the ciliated pits (A) are of a more rounded form. 
Fig. 13. Longitudinal section in the plane of the body of Bipalium Diana through the 
ciliated pits. Drawn with the camera. Slightly stained spaces appear to run 
to the pits ; between the light spaces is a peculiar tissue formed of small 
spindle-shaped cells. 
Fig. 14. Section of the glandular lining of the digestive tract of Planaria torva, from a 
transverse section of the animal’s body. Drawn with the camera lucida. 
Made from an alcoholic preparation. 
Fig. 15. Section of the glandular lining of the digestive tract of Bipalium Diana, from 
a transverse section of a specimen hardened in chromic acid. Drawn with 
the camera lucida. From the region of the mouth. 
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