994 ON POLYCH ATA FROM THE N.E, PACIFIC. 
Prats V. 
Phyllochetopterus prolifica. 
A series of three individuals showing the stages in the regeneration of the anterior 
region by a posterior fragment containing segments of the median and posterior 
regions. 
Fig. 12. Beginning of regeneration : anterior region represented by a tiny stump. 
Sermentation is indicated by the superficial folds, and the peristomial 
tentacles are seen as two apical outgrowths. 
13. Anterior region is almost complete, but still very small: peristomial 
tentacles short and fourth segment without enlarged sete. 
14, Adult worm with fully formed anterior region. Tentacles completely 
developed. The whole of the posterior region is not shown. 
PratE VI. 
Phyllochetopterus anglica, sp. i. 
Fig.15. A colony containing two fully developed worms. It consists of two 
parallel tubes with short connection. One tube shows the rounded 
original end. Natural size. 
16. A colony consisting of several parallel connected tubes, in part adherent to 
each other. Only one worm was found inhabiting it. Natural size. 
(In both figures, the anterior and median regions of the worm are shown dotted, 
the posterior region black, The tentacles are shown. ‘The tubes where they 
are transparent are shown unshaded, where opaque darkly shaded.) 
