146 



MANUAL OF ZOOLOGY 



SECT. V 



guishable into (esophagus, with longitudinally folded walls, 

 and intestine, with lateral caca (div.}. It ends in an anal 

 opening (a.) situated near the posterior extremity of the body. 



FIG. 73. Diagram of the organs of a Nemertine, from below, a. anus ; br. brain ; 

 div. cxca. ; long. ne. longitudinal nerve-cords ; m. mouth ; . nephridia ; ov. 

 ovaries ; pr. proboscis. (After Hubrecht.) 



The Nemerteans possess a system of blood-vessels with 

 well-defined walls. There are three principal longitudinal 



