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 10 PROCEEDINGS OF THE NATIONAL MUSEUM vol.75 



Remarks. — The clitellum is usually on x-xiii, but occasionally 

 extends onto ix and xiv. The male porophores appear to be charac- 

 teristic but the other genital markings vary considerably, as in other 

 species of this genus. Many of the Mandalay worms have a small 

 whitish depression on each side on segments x and xi in line with the 

 male porophore. Occasionally the two depressions of x are confluent 

 at the center to form a single elongate depression. In some of the 

 specimens glandular areas are present in the region of the depressions 

 or the depression may be lacking and the glandular areas slightly 

 elevated. Oval, smooth-surfaced, concave areas similar to the one 

 on xii in the type-specimen may occur on ix, xi, xii, or xiii. In 

 specimens collected at Prome and Thayetmyo the unpaired' markings 

 on ix and xii are slightly different in appearance, extending through 

 all of region cc on the posterior portion of the segment which is 

 enlarged to 4-6 times the width of the segment anterior to the setae. 

 Occasionally the setae are included in the anterior border of the 

 marking. The outer ends of these markings are more bluntly 

 rounded than those on the Mandalay specimens. 



The two gizzards are in segment xv and xvi or xvi and xvii. 



The prostates are sessile and project into the body cavity only very 

 slightly. 



This worm is very similar to D. rara, with which it may eventually 

 have to be included. It is to be distinguished from the latter species 

 chiefly by the appearance of the male porophores, the position and 

 character of the genital markings, and the smaller number of gizzards. 



DRAWroA FLEXA, new species 



Description of the type-specimen, external characteristics (Cat. No 

 19252, U.S. N.M.).— Length, 104 mm. Diameter, 3>^-5 mm. Num- 

 ber of segments, 238. Color: Grayish white, except on the clitellum 

 where the segments are reddish. 



The prostomium is prolobous. 



Segment vii has a deep secondary furrow posterior to the setae. 

 Segments viii, ix, etc., posteriorly, have two secondary furrows per 

 segment, one anterior to and one posterior to the setae of the segment. 



Dorsal pores are lacking. 



The setae begin on segment ii and are closely paired; ah is equal 

 to cd, aa is greater than be, dd is slightly greater than one-half of the 

 circumference. 



The clitellum is on x-xiii. 



The male pores are on 10/11, in be, slightly nearer b than c, and are 

 surrounded by slight, whitish, glandular elevations on x and xi. 



The female apertures are in 11/12, just external to b. 



The spermathecal pores are in 7/8, just internal to c. 



