452 E. A. ANDREWS. 
inserted obliquely, so that its median plane is not vertical, but 
inclined so that the right side is turned downward and the left 
side upward. It is so attached as to occupy all the space 
between parapodia 29 and 30, and then extends upward some- 
what upon the dorsal aspect of the trunk, so that its left or 
more posterior face is continued out from the dorsal surface of 
the somite 30 where it joins 29. Ventrally the attachment 
extends no further than the ventral part of the parapodia. The 
parapodia upon the left of the bud, near its base, overhang the 
back of the main terminal. 
The length of the lateral terminal is 2} mm., that of the 
entire main axis 12 mm., of which 9 mm. is anterior to the 
point of bifurcation and 3 mm. posterior to it. 
The main axis has 42 somites, of which the last three are 
quite small and young; 29 are anterior to the bifurcation, and 
13 posterior to it. The lateral terminal also has 13 normal 
somites, and an anal piece on which the anal cirri are lacking, 
from accident apparently. 
Owing to the rupture of the body in dying, no idea of the 
internal anatomy of the point of divarication of the terminals 
was obtained. Both terminals have the normal internal organs, 
even ovaries, as above stated. 
The specimen Y was taken amongst two or three hundred, 
August 3rd. It has the general appearance of W, as shown 
in Fig. 15. 
Of medium size, it swam about actively or crawled upon the 
bottom of the aquarium. 
The main trunk has 27 setigerous segments, the ventral 
terminal 6, and the dorsal 7, but it is truncated by the loss of 
its normal tip and several somites. 
The dorsal terminal is much stouter and longer than the 
ventralone. The latter does not extend across the entire width 
of the trunk, but arises as a sort of outgrowth from the left half 
of the ventral face. 
The somites 25, 26, 27, are contracted and narrow from side 
to side ; 25 and 26, judging from the appearance of the para- 
podia, have been injured upon the right side. 
