Glyphidrilus vangthongensis Chanabun & Panha 2013

Dimensions: body length 116 mm, diameter 7.5 mm in segment 8 and 8.0 mm before the clitellar wi in segment 24, 8.2 mm after wi in segment 32 in clitellar region; body cylindrical in anterior part, quadrangular in transverse section behind clitellum. 251 segments. Body colour pale brown with variations from red to pink at adjacent tissues of wi portion in different individuals of newly collected specimens. At posterior end dorsal surface considerably broader than the ventral. Clitellar wi on ventro-lateral part of clitellum in 25–31, 3.1 mm in height, and about 0.4 mm in width on both sides. Prostomium zygolobous. Dorsal pores absent. Clitellum annular in 12–40. Four pairs of setae per segment from 2, setal formula aa:ab:bc:cd:dd = 2.0:0.5:1.8:2.0:2.8 in segment 8 and 1.5:0.4:1.6:0.6:2.1 in postclitellar segments. Female pores, male pores and spermathecal pores not visible. Gm laterally paired or asymmetrical on bc in 15–17, 19, 24, and 32, and median paired on aa in 12–13 and 32–33. Septa 5/6–7/8 thicker, 8/9–10/11 thick and 11/12 to the last segment thin. Gi small globular within 7–8. Intestine enlarged from 14. Dorsal blood vessel anterior to 7. He in 7–11. No distinguishable np in first eleven segments. Sv in 9–12, with the pairs in segments 9 and 11 larger than the others. Ov in 13. Prostate and accessory glands absent. Sc in 12/13–18/19, two to thirteen on each side per segment.

The new species is known from the type locality in the river banks of Sakulnothayan waterfall and Wanathara Resort, Vangthong, and Chadthakan waterfall, Chadthakan, Phitsanulok, Thailand. This species was found on the shore but in proximity to the river water, in loamy sand topsoil (88.2% sand, 10.2% silt, 1.6% clay, pH 7.5–7.6) and also under the water at about 10–15 cm depth. The soil surface was covered with worm casts near the river banks.