Body slender, slightly prismatic. Adult specimens are 56 and 58 mm long and 0.8 mm thick (1 mm at the cilitellum). Segments without evident secondary annulation to about 120. No cutaneous pigment, body wall transparent. Prostomium zygolobous, semicircular. No dorsal pores. Nephridial pores maybe on the lateral line. Male and females pores not perceptible externally, but paired at 11/12 and 12/13 respectively, near the setal line ab. Three spermathecal pores along the middle dorsal line at 6/7, 7/8, 8/9. Two pairs of ventral setae on all segments (peristomium excepted), the dorsal setae disappear from segment 40 onward.
No gizzard, no typhlosole, no calciferous glands. Septal glands in 4, 5. Septa thin, the anterior ones funnel-shaped. Holonephridia begin in 16 or 17, covered by vesicular peritoneal cells. The setae ab of 11-15 are implanted in small glandular pads. There is a single pair of testes situated in the fore part of 11 and a single pair of seminal vesicles derived from 11-12, which penetrates the ovarian sacs, filling them almost completely. Ciliated seminiferous funnels are situated in the ventral lip of sperm sacs. There is a single pair of ovaries in the front part of 13 followed by a pair of long ovarian sacs derived from 13-14. Left ovarian sacs reach 26-30. Unpaired spermathecal pores open in 6/7-8/9 along the dorso-median line. Ampulla pyriform. Anterior spermatheca bilobed and smaller. The posterior one is bigger.