NOTES ON DISTOMA ENDEMIOÜM. 55 



( irimpertrichtcr) but no ciliary patches in the lumen of the vessels. 



The brain (^J".) is situated, not above or in front of pharynx as is 

 usual, but immediately behind it forming a bridge over the œsophagus. 



Sexual organs. The ovarium ( ov.) is a lobed organ of no defi- 

 nite configuration, situated at the beginning of the last J. of the 

 body. It lies nearer the ventral side than the dorsal. A very fine 

 oviduct arises from its dorsal side (vide fig. 2) and soon turns forward 

 in order to become continuous with the uterus. At the turning-point 

 it is joined by the Laurer's canal and soon afterwards by the median 

 duct of the vitellarium. The oviduct docs not show any special 

 widening that might be designated as ootyp. Unicellular shell-glands 

 ( sh. g, fig. 2 ) are grouped together in front of the ovarium. They 

 do not color very strongly and seem to have been hitherto entirely 

 overlooked. 



The Laurer's canal ( /. c.) opens on the dorsal surface by means of 

 a minute pore, after it has pursued an irregular course posteriorly and 

 dorsally. 



Shortly before its junction with the oviduct the Laurer's canal 

 stands in connection with a large oval or pear-shaped seminal receptacle 

 (s. r.), usually lying to the right of the median line. I always found 

 it filled with spermatozoa. In preserved specimens the mass of sper- 

 matozoa has contracted, thus leaving a space between it and the 

 receptacular wall. It is this organ that has hitherto been taken for 

 the ovary. 



The vitellarium (uiV.) on each side of the body consists of 

 numerous small groups of yolk-cells, presenting a clustery appearance. 

 It extends through all that part included between the ovary and the 

 ventral sucker, along the body-margin outside of the intestinal tube. 

 Sections show that it is confined to the dorsal side of the body. I did 

 not happen to notice it arranged in separate coils, nor did I perceive any 



