188 



MEMOIRS OF THE QUEENSLAND MUSEUM. 



The musculature of the neck and scolex calls for notice. In the anterior 

 neck region, the longitudinal muscles are very abundant and are seen, in trans- 

 verse section, to be cut transversely as well as obliquely (text-fig. 8), as they 

 pass forwards to become inserted into various parts of the scolex. There is a 

 Avell-defined zone containing the muscles (text-fig. 7), and this lies just within 

 the region provided with calcareous corpuscles. It occupies the wliole central 

 region, though the fil)res are rather less abundant in the centre of the section 

 and in the inunediate vicinitv of the nerves and excretorv vessels. The bundles 



vv 



sclm 



Fig. 5. — T.S. posterior region of scolex, showing transverse muscle fibres (tr.m.f.). v.v. = 

 ventral excretory canal. 



Pig. 6. — T.S. behind fig. 5, showing disposition of the longitudinal muscles [l.m.), also the 

 l^resenee of weak transverse fibres {m.f.) in the cortex dorsally and ventrally. 



elsewhere are strongly developed and very numerous, so tliat there is practically 

 no differentiation into medulla and cortex within the nuiscular zone, though the 

 outer cortical area is well defined since it is free from inuscular fibres and 

 contains calcareous corpuscles. In this region certain of the excretory canals 

 (the dorsal) have their walls well supplied with longitudinal muscle fibres 

 (fig. 9). There is no definite arrangement of the muscles in the neck region. 



Fig. 7. — T.S. neck, showing two dorsal excretory canals {d.v.) on one side and three on 

 the other. The outer limit of the longitudinal musculature is sho'mi by the dotted line. v.v. = 

 ventral excretory vessels. 



Fig. 8. — ^T.S. neck posteriorly to Fig. 7, showing arrangement of the excretory vessels and 

 mviscles. There are two dorsal canals on one side and one on the other. 



