NEMERTEANS 



287 



net. Brinkmann gives sixteen nerves. I have examined my series of sections for the 

 rudimentary eyes and in two males several small organs corresponding to the description 

 and figures (Brinkmann, 1917) were found on each side of the lappet of the body 

 ventrally very close beside the rhynchodaeum, but I could not trace them in the female. 



Genus Probalaenanemertes, Brinkmann 



Probalaenanemertes irenae, n.sp. (Figs. 64, 65). 



Two specimens of this form were collected at St. 89. The colour notes were " scarlet 

 with orange spots down sides" (N 161); "pale orange with deep rose pink spots down 

 sides" (N 162). In spirit the sizes were: length 9-0 and 17-0 mm.; greatest breadth 

 3-0, 3-5 mm.; thickness 17, 2-0 mm. Both were somewhat flattened, bluntly pointed 

 at the thicker end of the body and with a distinctly flat spade-shaped tail (Fig. 64). In 



A B 



Fig. 64. Probalaenanemertes irenae, n.sp. Outline sketches of the preserved specimens. 

 A, N 161, dorsal; B, lateral; C, N 162, lateral, x 4 approx. 



one five brownish gonads could be seen on each side and the lateral nerves were faintly 

 visible outside them ; in the other there were fourteen gonads on one side, twelve on the 

 other. The colour was pale brown and the bodies were translucent. 



Anatomy (Fig. 65). The epithelium is present in patches at the anterior end and is a 

 deep layer into which the serrated basement layer penetrates deeply (Fig. 65 A). The 

 circular and longitudinal muscles are very much reduced, especially the former. At the 

 tail there are dorsal and ventral median strengthening strands of longitudinal muscle 

 (Fig. 65 C). There is no oesophagus. The folded tube shown in Fig. 65 A passes back 

 unbranched through the brain region and beyond. Meanwhile two gut branches have 

 appeared above and lateral to the brain and farther back more appear which invade the 



