438 
V. A. POTTS. 
bably have asiug’le segment. In the remaining individual of 
T. gemmipara (Text-fig. 5) it is impossible to trace the 
limits of the proliferating zone. It seems, then, usual for the 
cushion to be formed from the ventral surface of two segments. 
But variability is so great in the transverse situation of 
the cushion that it probably occurs too in its longitudinal 
extension. It seems, however, quite certain that the 
proliferation takes place at the terminal segments, and not, 
as Johnson supposed, at a segment some distance from the 
Text-fig. 8. 
Part of section adjacent to that represented in Text-fig. 7, showing 
anus of stock. 
end, for the genital appendage of T. gemmipara is also a 
recent growth from these same terminal segments. 
The occurrence of gonads in the genital appen- 
dage and the stock itself. — The salient facts in the struc- 
ture of the genital appendage of T. gemmipara have been 
correctly stated by Johnson and are quoted above. In my 
specimen (VIII) it may, however, be mentioned, a pair of 
gonads is developed in every segment, and also in two pre- 
ceding segments of the stock itself (Text-fig. 7). The occur- 
rence of sexual products in the last segments of the stock is 
