22 



EISEN 



mathecae with long narrow duct and a long narrow ampulla, at the junc- 

 tion of the two a diverticle, variable in size, but always very minute. 

 Sperm-ducts about eight times as long as the cylindrical and slightly 

 curved funnel ; atrium with five medium-size atrial glands opening in 

 one plane near the upper end of the atrium. No accessory glands, but 



numerous penial 

 glands inside the 

 penial bulb. Two 

 long sperm -sacs ex- 

 tending far back- 

 ward. One ovisac. 

 Nephridia with un- 

 usually large neph- 

 rostome. Lympho- 

 cytes small, ellip- 

 soidal, pointed. 

 Color pale yellow 

 (alcoholic speci- 

 mens) . 



Distribution. 

 Chuckches' Land, 

 to west of Bering 

 Strait, Asia. Col- 

 lected during the 

 Vega Expedition 

 under Baron A. E. 

 Nordenskiold, by 

 Dr. Anton Stux- 

 berg, at 4 Jinretlen,' 

 June 15, 1879. 



Characteristics . 

 The shape of the 



spermathecae, with their single diverticle and the posterior emargina- 

 tion of the brain, are the leading characteristics of this well-defined 

 species. The large nephrostome distinguishes the species from Jlf. 

 Jlavus Lev, which is said by Michaelsen to possess a small narrow 

 anteseptal. The sperm-duct is much longer than in M. Jlavus. 



DETAILED DESCRIPTION. 



Setce. All of equal length; at least no large specialized setae; 

 average number in ventral fascicles 4. 



FIG. 2. Mesenchytrceus asiattcus. 



