162 



spherical nucleus lies in the base of each cell, usually in one of the 

 broader angles made by the curves of the intracellular canal. Inter- 

 stitial cells are absent. 



The characters of the chylus cells are uniform, and tend to con- 

 firm Eisen's conclusion that they have taxonomic value. A compari- 

 son with other species in which the chylus cells have been worked out 

 shows that in none of them do these cells resemble closely those of 

 oconeensis. 



Nephridia. — The nephridia are rather large and conspicuous. The 

 anteseptal part (PI. X, Fig. 36) is approximately as large as the post- 

 septal part. The first pair appears on VI/VII. The efferent duct 

 arises from the postseptal part a short distance from the septum and 

 opens exteriorly just anterior to the ventral setae bundles. The lumen 

 is very tortuous throughout its entire length. 



Speriniducal Funnel. — The spermiducal funnel (PI. XI, Fig. 40) 

 is cylindrical. The posterior end diminishes uniformly to the diam- 

 eter of the sperm duct which arises from it. The anterior end is char- 

 acterized by a well-developed protruding funnel-shaped collar, dis- 

 tinctly set off by a transverse constriction. The length of the funnel 

 is about twice its diameter. It lies in the usual position, with the 

 anterior end pointing dorso-cephalad owing to the distinct bend in 

 the body of the funnel. The lumen is eccentric as shown in trans- 

 verse section, being nearest the ectal surface of the organ. 



Pcnial Bulb. — The structure of the penial bulb (PI. XI, Fig. 42) 

 conforms to the lumbricillid type as defined, by Eisen. It is composed 

 of cells of one kind only. Each cell has two parts; the main body, 

 which lies near the periphery of the bulb and contains a large oval 

 nucleus, and the prolongation, which reaches to the penial lumen. The 

 body of each cell has a strong affinity for stains, while the prolonga- 

 tion stains only very slightly. The sperm duct unites with the bulb 

 on the dorso-ectal surface, where it meets the penial lumen. The 

 bulb is covered by a well-developed musculature. The general struc- 

 ture of this organ is the same as in Fridericia tenera Smith and Welch, 

 but when the two bulbs are carefully compared, distinct differences 

 appear in shape, in the mode of union of the sperm duct with the bulb, 

 in the musculature, and in the character of the component cells. 



Spcnnathcccc. — Each spermatheca ( PI. X, Fig. 37) has three well- 

 differentiated parts; the duct, the ampulla, and the diverticula. The 

 duct opens laterad in IV/V. Two or three inconspicuous unicellular 

 glands occur at this opening, but they are so small that high magnifica- 

 tion is required to distinguish them. The duct is approximatelv uni- 

 form in diameter throughout its length and is usually more than twice 



