Key to the species of Tonoscolex Gates, 1933 from India (modified from Gates, 1972)

1 Setae lumbricine, eight on each segment................................................................... 2

- Setae perichaetine, more than eight on each segment......................................................... 7

2 Five pairs of calciferous glands.......................................................................... 3

- Four or less than four pairs of calciferous glands............................................................. 4

3 One pair of spermathecal pores in intersegmental furrow 7/8............................. T. kalimpongensis sp. nov.

- Two pairs of spermathecal pores in intersegmental furrows 6/7 & 7/8.................................. T. monorchis

4 Three pairs of calciferous glands in segments 10–12; three pairs of seminal vesicles in segments 8, 9 & 12...... T. indicus

- Four pairs of calciferous glands in segments 9–12; two pairs of seminal vesicles in segments 10 & 11.................. 5

5. Spermathecal ducts straight...................................................................... T. striatus

- Spermathecal ducts looped.............................................................................. 6

6 Seminal grooves in segments 16–17............................................................ T. michaelseni

- Seminal grooves in segments 17–18................................................................ T. oneili

7 Five pairs of calciferous glands in segments 8–12.................................................. T. kabakensis

- Three pairs of calciferous glands in segments 10–12..................................................... T. horai