NEMERTEANS 



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the head there are small round eosinophile cells scattered among the muscle strands. 

 These apparently open into the rhynchodaeum. The tissues of the body cavity stain 

 deeply with haematoxylin or carmine, giving the impression of a thick mucus in which 

 deeply staining granules are embedded. 



The epithelium is very thick. The basement membrane is a little thicker than the 

 circular muscle layer. It is homogeneous in appearance and stains with eosin. The 

 longitudinal muscle layer is somewhat thicker than the epithelium and the fibres are 

 packed in conspicuous bundles. The ganglia are enveloped in a coat of longitudinal 

 fibres. In the body behind the brain this muscle layer splits into bundles which pass 

 gradually outwards and rejoin the longitudinal layer of the body. The eyes are just inside 

 the muscles, embedded in the connective tissue. 



A 



Fig. 11. Emplectonema ophiocephala (Schmarda). A, sketch of head cleared in cedar oil; B, head cleared 

 in cedar oil, dorso-lateral view to show the eyespots; C, armature, cleared in cedar oil. 



The rhynchocoel does not extend beyond the anterior third of the body. The pro- 

 boscis is short and thin. Both rhynchocoel and proboscis are greatly restricted by the 

 closely opposed ganglia. The armature appears to vary. Two accessory stylet reservoirs 

 are always present, but the number of stylets differs. In two worms of nearly the same 

 size taken at the same time, the accessory stylets numbered one and two in one, and 

 eight and nine in the other (Fig. 11C). A third specimen possessed two and three 

 stylets. There is a stout main stylet mounted on a slightly hour-glass-shaped base 

 shorter than the stylet itself. 



Vascular system. There are two lateral vessels in the head. They have not been traced 

 at the ganglia, but the blood is responsible for the colour of the brain in the living animal, 

 so the vessels are broken up into fine branches. Directly behind the brain there are two 



