ZooL.— Vol. II.] RISEN— OLIGOCH^TA. 137 



very large papilla of the Y-gland, is free. Owing to con- 

 tractions and contortions of the worm, it is difficult to 

 illustrate the true position of these exterior organs (figs. 

 29-33). The papilla of the Y-gland is very large, filling 

 nearly the whole of the bursa-copulatrix. It possesses only 

 one pore, the one which communicates directly with the 

 duct from the Y-gland. The penis is variable in regard to 

 its curvature^ but it is always so situated that its exterior 

 groove can be readily brought opposite and close to the 

 opening pore of the Y-gland. When vicAving the papilla of 

 this gland from the exterior there appear to exist two 

 external pores of the gland, the papilla being pointed at 

 both ends and quite symmetrical. Sections show, however, 

 that there is only a single pore, which is always situated on 

 the side nearest the exterior groove in the penis. This 

 groove in the penis does not extend to the base of that 

 organ, but only about half-way down its length. The groove 

 is connected with the lumen of the penis near its apex only 

 and not at the base also, as described by Beddard. 



Internal Characters. 



Nephridia. — The nephridia are very thin, slender, and 

 even, occupying a narrow zone along the septa. Those 

 posterior to the clitellum are long and covered for their 

 entire length with a thick but even agglomeration of round 

 granular secretions of different sizes. These globules 

 stain intensely with aniline colors. The granules are 

 confined in a sac-like tissue, the surface of which is race- 

 mose. It extends from top to base of the nephridium, but 

 only along one of its sides. The nephridial coelomic sac, 

 which follows the almost parallel lobes, is narrow and even, 

 and occupies about one-fourth of the width of the somite. 



Su^ra^haryngeal Gland. — The usual suprapharyngeal 

 glands are present and well developed. When viewed in 

 longitudinal sections they are seen to consist of five distinct 

 lobes, one posterior to the other. The most anterior lobe 

 is the smallest and the most posterior lobe the largest. Each 



