KXPI.ANATION OF PLATE XV. 



Fig. I. General view of Nais variabilis, var. punjabensis. 



,, 2. Anterior part of body of Nais variabilis, var. punjabensis, seen from 

 the side. 



,, 3. Head of Nais variabilis, var. punjabensis, to show eyes and *'Neben- 

 augen." 



,, 4. Posterior end of Nais variabilis, var. punjabensis. 



,, 5. Zone of budding in Nais variabilis, var. punjabensis, to show the 

 intercalated segments. 



,, 6. Budding zone at the posterior end of Nais variabilis, var. punjabensis. 



,, 7. Ventral seta of Nais variabilis, var. punjabensis. 



,, 8. An ordinary example of a dorsal seta of Nais variabilis, var. punjab- 

 ensis, with thorn-like processes. 



