633 



ally the cell walls are distinct. When retracted, the duct enters the 

 bulb well clown on the ental side and extends through it to the ex- 

 terior opening at the edge of the invagination. In the everted condi- 

 tion the lateral part of the bulb is depressed, the invaginated surface 

 becoming superficial, the bulb becoming more globular in shape, the 

 position of the entrance of the duct being shifted to the dorsal side 

 of the bulb, and the duct extending directly to the ectal surface. 

 Apparently the cells of the bulb are all of one kind, and all extend 

 to the surface of the bulb, none ha^■ing■ been found emptying into the 

 duct. 



Speniiatheccu. — A pair of these organs is present in V. Each 

 spermatheca (PI. CII, Fig. 35) consists of a well-defined duct and an 

 ampulla. The ectal opening of the duct is in the intersegmental 

 groove IV/V, and is latero-ventrad in position. No definite glands 

 are present at the ectal opening. The wall of the duct is thick, and 

 shows a number of large nuclei scattered throughout its length. The 

 lumen is very fine. The duct is nearly straight, extending directly 

 to the dorsal side of the digestive tract, where it expands to form 

 the ampulla. The ovoid ampulla forms a closed sac, having no con- 

 nection with the digestive tract. Its walls are quite thin, and in all 

 of the specimens exam:ned it was partially or entirely filled with 

 sperm cells. 



