106 F. G. HEATHCOTE. 
Fic. 10.—Longitudinal section through a segment of the heart. art. 
Artery. ost. Osteum. 
Fic, 11.—Transverse section through heart. ext. cu¢. External cuticle. 
ext. w. ht. External wall of heart. dé. Internal lining of heart. m. w. ht. 
Muscular wall of heart. msc. Muscle-fibres from the heart to the fat- 
bodies, forming a sort of pericardium. susp. musc. Suspensory muscle of the 
heart. 
Fig. 12.—Section through the nerve-cord. gc. Ganglionic part. uc. 
Fibrous part. 
Fic. 13.—Section through region of eye, showing two eye-spots and the 
lens of another. 7.c. Retinal cells. czzer pgt. Pigment round the base of 
the crystalline cones. 7. Lens. 4.c. Cells of the hypodermis. pgt. Pigment 
around the base of the retinal cells. 
Fig. 14.—Section through the region of the eyes, showing one spot cut 
horizontally and one longitudinally. 4. An eye-spot cut longitudinally. 2B. 
An eye-spot cut transversely. 7. Lens. pgt. Pigment. c. Crystalline cones. 
