606 W. S. NKJKEKSON, 



in a geiierally struiglit course to the region of dorsal flexure where it 

 bends upward. It opens into the tubulär depression at the posterioi- 

 eud of the body already described as receiviiig the opeuings froni the 

 two excretory vesicles. The opening of Laurer's caoal is median, 

 between those from the excretory vesicles, and from the anterior or 

 dorsal side. This method of opening to the exterior in common with 

 the excretory System is peculiar the only similar case with which I 

 am acquainted being one described and figured by Looss ('99, fig. 71, 

 tab. 30) and occurring in an Egyptian species of Urogonimus. 



Both MoNTicELLi ('92) and Braun ('89— '93) in giving the cha- 

 racteristics of the family Aspidobothridae State that Laurer's canal 

 is absent, Yet Voeltzkow ('88) described as a "receptaculura vitelli" 

 a structure in Aspidogaster conchicola which Braun recognized as a 

 moditied Laurer's canal. Stafford ('96) described the same orgau 

 as a Laurer's canal. Jägerskiöld ('99) states that Laurer's canal 

 is i)resent in Macraspis. With my discovery of its presence in Cotylo- 

 gaster it is now known to occur in at least half of the genera com- 

 prising the family. This will necessitate a modification of the State- 

 ment of family characteristics as given heretofore. 



The oviduct is joined by the unpaired vitellary duct just before 

 entering the shell gland. The latter organ is situated a short distance 

 anterior and to the left of the ovary in the median plane. 



Immediately after emerging from the shell gland the uterus turns 

 caudad and enlarges to form a considerable Chamber fiilled with sperm 

 — the receptaculum seminis uterinum. The pari of the uterus follow- 

 ing this enlargement is long and tortuous Alling most of the space 

 between and around the other organs. It is impossible to follow its 

 windings but the condition of the contained eggs and embryos may 

 be used as a means for determining its general arrangement. Its 

 course as made out by this means is represented in the diagram 

 (Fig, 15). The ova pass backward from the vicinity of the shell gland 

 in or a little to the left of the median line nearly to the posterior 

 end then across to the right side and forward to near the anterior 

 end; here they cross in front of the shell gland to the left side and 

 again backward along that side to the posterior eud of the inner 

 muscular tube. Within this they pass forward, the anterior portion of 

 the Uterus here lying ventral to the intestine and on the left of the 

 vas deferens. The terminal portion of the uterus (vagina?) is sur- 

 rounded by a thick sheath of elongated gland cells corresponding with 

 those in C. michaelis which Monticelli called "glandole glutinipare". 



