232 CALIFORNIA ACADEMY OF SCIENCES. 



vii), are veiy large, filling the greater part of the cav- 

 ity. The gland in somite viii is so much reduced in 

 height that it is readily hidden in the folds of the sep- 

 tum. The anterior gland in somite v is much higher 

 (fig. 45) than the other glands, and extended in the direc- 

 tion of the pharynx which it reaches and (when the 

 worm is contracted) apparently partly overlaps. 



The septal glands in somites vi, vii and viii are at- 

 tached to the septum and the oesophagus. From this 

 central base the gland extends in all directions, com- 

 pletely surrounding the oesophagus, while numerous mus- 

 cular bands connect it with the body-wall of the next 

 posterior somite. In a transversal section the gland is 

 seen to be a composite one consisting of four or more 

 lobes or parts (fig. 22, O. occidentalis) , which are con- 

 nected at oesophagus, but at their outer extremities are 

 free. Each part is grouped around a muscular band, 

 which passes through the gland and at the free apex of 

 the gland passes into another muscular band which takes 

 its origin on the surface of gland. Both pass then as one 

 muscle through the posterior septum and connect with 

 the parietes of the posterior somite. 



The muscles of the two larger glands in somite v pass 

 through a whole posterior somite and two septa before 

 connecting with the body-wall. The upper, centrally 

 located, glands in somite v differ from the other glands 

 by being grouped around a pair of muscular bands which 

 head on the pharynx and transversing the glands, pene- 

 trate the posterior septum and somite in a way similar to 

 what takes place in the other glands. The effect of this 

 arrangement is such as to cause the posterior glands to 

 be flattened out against the septum, while the anterior 

 gland is stretched out towards the pharynx in the 

 opposite direction (fig. 45). This movement is con- 



