NEMERTEANS 



153 



ac 



cells. This portion of esophagus is highly muscular and somewhat 

 barrel-shaped (fig. 5, e) , projecting a little way backward into the broad 

 intestine which immediately follows posteriorly. Its posterior portion 

 is therefore surrounded by the intestine, indicating rudiments of the 

 intestinal caeca found in other genera. Intestinal canal broad, with 

 short lateral pouches 

 which become very 

 much reduced toward 

 posterior end of body. 



Nervous System . 

 The nervous system 

 shows few deviations 

 from that in related gen- 

 era. Brain fairly well 

 developed. From dor- 

 sal lobes a pair of large 

 nerves pass anteriorly to 

 eyes and anterior por- 

 tions of head. These 

 are easily seen in living 

 worms. No indications 

 of cerebral sense organs 

 were found either when 

 the specimens were 

 stained in toto or when 

 examined in sections. 



Reproductive Or- 

 gans. The pouches of FlG lg> c efialt{ Horizontal section through 

 genital products become anterior portion of body ; somewhat diagrammatic ; 

 enormously developed eg, cephalic glands, ac, me, pc, anterior, middle and 

 and encroach greatly posterior chambers of proboscis. X "5- 

 upon the intestinal canal at time of sexual maturity (pi. xix, figs. 7, 

 8). Genital pouches extend farther forward than in almost any other 

 Nemertean, reaching very nearly to brain. Ovaries (fig. 7, ov) regu- 

 larly paired, with a single large pouch containing usually from twelve 

 to thirty ova between each pair of intestinal lobes. Spcrmaries, on 

 the other hand, far more numerous, surrounding intestinal canal on all 

 sides. As many as fifteen or more separate spermarics (fig. 8, t ) are 

 sometimes found in a single transverse section of the body. As in 

 most parasitic animals the abundance of sexual products is greatly in 

 excess of that in related nonparasitic forms. 



