26 CALIFORNIA ACADEMY OF SCIENCES. 
while the three anterior pepto-nephridio-pores are in front of the fourth sete (fig 2). 
Clitellum is conspicious, occupying somites xiy to xvii, encroaching slightly on xiii 
(fig. 2 and 15). 
In viewing the caudal end of the live worm a number of irregular white spots 
are seen in mature specimens. ‘These are rows of mature ova which agglomerate there 
sometimes in large quantities. How they finally find their way through the oviduct 
is not readily explained. 
Sete (figs. 2 and 4). As usual the sete begin in somite 1. All except 
those in the penial sacs, are sigmoid and arranged in couples of two, eight in each 
somite. The ventral setee are about 4 closer than the lateral ones. Thus if we con- 
sider the distance between the inner and outer couples to be 50, that between the 
sete of the outer couple is 50, that between the setee of the inner couple 22, that be- 
tween the inner couples 40. This being the distance in somite xxvii, where it may 
be said to be normal. In the region of the clitellum, and posterior to it, the inner 
setee are unequally distant in the respective somites. Thus we may consider the inner 
setee 1 and 2, to have the normal distance from each other in somites xii to xxvii. 
From these two somites the sete in the inner couples conyerge toward somite 
xviii in which the sete are about 4 as far apart as in xii and xxvii. In xyii the sete 
of the inner couples are wanting. 
The innermost or row No. 1, forms a continuous line from one end of the body 
to the other, while the row No. 2, forms an angle with somites xvii and xviii at the 
apex. The sete in rows 3 and 4 are parallel and normal. The seta 1 in xviii is pre- 
sent (pl. xii, fig. 4). 
This arrangement of the sets appears very constant, and is characteristic of 
the species, the details being somewhat different in the other species of the genus, 
while the general characteristics are the same. The normal sete (fig. 16) of the 
clitellum are not smaller than those of other parts of the body. The penial setie are, 
however, very much the largest. 
Penial setw (fig. 17). The two pairs of sacs containing the penial sete are situated 
in front of the spermidueal pore in somite xvii. They open immediately in front of 
that pore, in a slit, at either end of which is situated a pore, each pore being the 
outlet for the respective fork of the penial sac. The two sacs are connected at the 
upper margin as usual by arciform muscles. Each sae contains not less than two, and 
sometimes three or four setie, straight or slightly curved, but not sigmoid. The sete 
vary considerably as regards shape, but resemble each other in not being sculptured, 
and are only marked by rings. The penial sac reaches to the upper part of the mus- 
cular part of the prostate. 
INTERIOR CHARACTERS. 
The Septa begin between somites iv and y. Those between vii and viii, and 
following as far back as somite xiv, are slightly thickened, all, however, being of the 
ame general thickness, 
The body wall contains the usual layers. The hypodermis is slightly thinner 
