COLLECTION OF NEMERTEANS FROM SINGAPORE. 115 



region of the black lines, is the pigment, which in sections is 

 seen to be brown. The cutis glands are well marked and 

 their contents stain deeply with thionin, though not at all 

 with carmalum. The gelatinous layer of the cutis is rich in 

 circular fibrils. 



The vascular system in the snout shows the wide hori- 

 zontal lacunae characteristic of the genus. These bend round 

 beneath the dorsal ganglion at its commencement, and, taking 

 an upward course, come to lie between the latter and the 

 proboscis sheath at the level where the proboscis is attached 

 (fig. 1, a). These lacunae then extend dorsally, and at the 

 posterior limit of the ventral commissure unite to form the 

 dorsal vessel, and also envelop the top of the dorsal gano-lion 

 (fig. 1, h). In this region a small diverticulum projects into 

 the tissue between the dorsal and ventral ganglia. This 

 diverticulum becomes separated off, and a few sections later 

 is seen to unite with its fellow of the opposite side, formino- 

 the median ventral oesophageal vessel (Schlundgefass) (fig. 1, 

 c). At this level the lacuna which earlier enveloped the 

 dorsal portion of the dorsal ganglion is now seen to lie upon 

 the dorsal surface of the cerebral organ. Still more dorsally 

 a portion of the lacuna has separated off, and this later unites 

 with the median oesophageal vessel on each side (fig. 1, d), 

 and the common lacuna so formed is continued into the 

 oesophageal lacunae. 



The alimentary canal is characterised by the great 

 thickness of the glandular tissue beneath the epithelium of 

 the oesophagus. In the intestinal region the lumen is wide. 

 The intestinal diverticula alternate in depth, every other one 

 being nearly twice the depth of those directly behind and in 

 front. The deeper set are not so deep as the width of the 

 lumen of the intestine. There is no ventral gutter. 



The proboscis shows a layer of diagonal muscles between 

 the circular and longitudinal layers. The longitudinal fibres 

 are characteristically arranged, recalling the condition seen 

 in transverse sections of Lumbricus. 



The proboscis sheath extends rather less than one third 



