176 PROCEEDINGS OF THE NATIONAL MUSEUM vol.84 



uniform rate of curvature in a sagittal plane with the convex side 

 directed anteriad. The length in a sectioned specimen is about 1 mm, 

 and the diameter midway of the length is about 0.015 mm and near 

 the proximal end 0.017 mm. The distal part tapers gradually near 

 the end and is finely sculptured. The distal ends protrude but very 

 little and are very closely approximated with the male pore and near 

 seta line h. 



Tlie prostomium is epilobic. The anterior five somites are bian- 

 nulate, and others are triannulate. The clitellum includes 13-18. 

 It is much thinner on the median ventral part of 13-15 and is un- 

 developed on 16-18 between seta lines a. Papillae are variable in 

 number and locations. Ventral median papillae of small size and 

 circular outline are found anterior to the male pores in 20 speci- 

 mens. In 14 of them, including the type, such papillae are found 

 only at 10/11. In three others such papillae are found at 10/11 

 and also at 15/16. In one specimen the papilla is at 9/10. In 

 another there are papillae at 9/10 and 10/11, and in the paratype 

 they are at 10/11 and 11/12. Posterior to the clitellum the papillae 

 are transversely elongate and the anterior pair are at 19/20 in line 

 with ab. Other pairs, when present, become progressively more 

 approximated and are sometimes in contact at the midventral line. 

 Each of 19 specimens has a pair on 19/20; in nine specimens there 

 is an additional pair on 20/21; and in two there is a third pair on 

 21/22. In one abnormal asymmetrical specimen, in which the organs 

 of a part of the left side are one somite anterior to the normal posi- 

 tion, there are four pairs of papillae, of which those of the left side 

 are at 18-21 and those of the right side at 19-22. The anterior 

 median papilla of this specimen is at 10/11. Dorsal pores are present 

 posterior to the clitellum, but none have been found in the anterior 

 somites. Nephridiopores are paired on each of most somites but 

 irregularly distributed. Some open on seta line d and others on 

 seta line c in the region in which sections were made. Each of the 

 pair of male pores on 18, laterad of the penial setae and closely 

 approximated with them, is located on the summit of an elevation in 

 seta line h. Oviducal pores are paired on 14 and located a little 

 anteriad of the setae and midway between the midventral line and 

 seta lines a. There are two pairs of spermathecal pores at 7/8 and 8/9 

 and in seta lines &. 



Internal characters. — The most strongly thickened septa are 7/8- 

 10/11; less thickened are 6/7 and 11/12. The dorsal wall of the 

 pharynx is much thickened and includes an evaginated chamber with 

 diverticula. A powerful gizzard is present in 5. The lining layer 

 of the esophagus in the anterior part forms longitudinal folds, ap- 

 proximately 15 in number. In the posterior part of somite 9 there 



