Further notes on the genus Microcotyle. 393 



worm. It lies about 0.4 mm behiiid the oral suckers. Behind it at 

 a distance of about 0,65 mm on the dorsal surface is the sac-like 

 orilice of the vagina which is also unarmed. From this there runs 

 backward a tortuous tube which alter forming' an enlarj^ement 

 opens into two lateral vaginal canals which eventually become the 

 lateral vitelline ducts. Posteriorly these begin to be filled with 

 j-olk material and enlarge until they reach the point at which 

 they unite. 



The ovary (Figs Aa and b) is mach longer and narrower and more 

 convoluted than in most of the other species studied. It form first 

 an irregulär Square across the middle of the worm and crossing to 

 the left side coils irregularly backward toward the left where the eggs 

 are most fuUy developed and the oviduct takes its origin. This 

 duct proceeds backward to receive the common vitelline duct but 

 gives oif on the way a canal which runs to the left. The ter- 

 mination of this canal could not be made out and it is not 

 shown in the drawing but it doubtless represents the seminal 

 reservoir. Having received the vitelline duct the oviduct passes 

 through the radiate shell gland into the bulbous uterus wlüch 

 then runs straight forward to the genital opening. The vitellaria 

 are voluminous and extend from opposite the vaginal opening to 

 the sucker disc. occupying both sides of the body. The festes, about 

 75 in number, extend nearly to the sucker disc, occupying the whole 

 of the middle of the body from the termination of the uterus back- 

 ward. The Vas deferens is large and tortuous and is usually filled 

 with spermatozoa. It passes forward to open at the genital pore 

 without the formation of any definite cirrus. 



The eggs are yellow and fusiform with one rather rounded end. 

 This is the posterior end and is not provided wäth a chitinous fila- 

 ment while the anterior end is pointed and exten ded into a very 

 long tangled lilament. 



Measurements are as follows: 



Length of worm: 12 to 13 mm. 



Width : 1,25 mm. 



Length and form of caudal disc: 4,5 mm triangulär. 



Average: 108 suckers. 



Diam. of suckers : 0,2 X 0,15. 



Testes: 75 in number. 



Size: 0,10 to 0,15. 



