References
- Gates , G. E. 1956 a . On another lumbricid earthworm with “relictus” characteristics and the disposition of Southern's species . Ann. Mag. Nat. Hist. , 9 ( 12 ) : 369 – 373 .
- Gates , G. E. 1958 b . On the origin of the biclitellate condition in lumbricid earthworms . Ann. Mag. Nat. Hist. , 9 ( 12 ) : 577 – 581 .