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PROCEEDINGS OF THE NATIONAL MUSEUM 



clitellum there are on many of the segments two slight secondary 

 furrows, one anterior to and the other posterior to the setae of the 

 segment. 



The first dorsal pore is in 10/11. Dorsal pores are also present 

 in 11/12 and from 17/18 posteriorly. There are pore like depressions 

 in 12/13 to 16/17 but no functional pores are present in these 

 furrows. 



The setae are eight to each segment, in four pairs, and begin on ii. 

 Anterior to the clitellum ah is about equal to cd, and be and aa are 

 about equal. Posterior to the clitellum ah is less than cd, and he is 

 less than aa. Toward the tail ah and cd tend to become equal, but 

 aa remains larger than he. The dorsal dis- 

 tance is slightly greater than one-half the 

 circumference. 



The clitellum extends from 13/14 to 17/18 

 (4). There are no intersegmental furrows vis- 

 ible between the clitellar segments. 



The male pores are on xvii in he, just exter- 

 nal to h. Each pore is on the center of a 

 smooth, glistening, flat-topped area which lies 

 at the bottom of a deep longitudinal depres- 

 sion in the region ah on segment xvii. 



The female aperture is single, on the left 

 side only, anterior to and very slightly inter- 

 nal to seta a. 



The spermathecal pores are one pair in 7/8 

 in the region cd. 



There are three genital markings. The 

 anteriormost is a circular area between setae 

 ah of segments xv and xvi and extending at the 

 middle to just beyond the setal lines h. This area is concave, lighter 

 in color than the rest of the clitellum, and sharply delimited by a 

 circumferential furrow. An area similarly colored and delimited and 

 also concave, but oval in shape lies across 18/19 from the setae of 

 xviii to the setae of xix and included between the setal lines hh. The 

 long axis of the oval area is perpendicular to the long axis of the 

 animal. The other marking is an oblong-shaped, whitish region 

 extending from the setae of xvi to the setae of xviii, with the longer 

 axis of the region along the long axis of the worm. The area is 

 sharply delimited by furrows only on the anterior and posterior 

 margins. In the region ah on each side is a deep longitudinal depres- 

 sion into the body wall. 



Internal anatomy. — Septa 4/5 and 5/6 are present and thickened, 

 the latter more than twice the thickness of the former; 6/7 and 7/8 



Figure 13.— Eutyphoeus 



BIFOVIS. QeNITAL area 



