74 CALIFORNIA ACADEMY OF SCIENCES. 
External pores. There are no dorsal pores. The spermathecal pores are 
found between somites vii/viii and viii/ix in front of seta 2, each one situated ona 
slightly elevated cushion. The ovipore in xiy in front of seta 1. The male pores are 
in xviii in front of and in line with seta 2 (fig. 266). The nephropores are in front 
of seta 2. 
Setw. The setse commence in somite ii, eight in each segment and in couples. 
The distance between 3 and 4 is only slightly larger than that between 1 and 2. The 
distance between 1 and 1 is nearly twice as large as that between 1 and 2, and the 
distance between 2 and 3 is a little smaller than that between 1 and 1 (fig. 27). 
Color of body pale flesh, rather transparent and marbled very much like 
Deltania. Clitellum yellowish. 
INTERNAL ANATOMY. 
Body-wall. The body-wall appears to me to be of unusual thinness, throughout 
the length of the body. The dorsal side is slightly thinner than the ventral side, at 
least anterior to the clitellum (fig. 29). Dorsally the longitudinal muscular layer is 
of about the same thickness as the transverse layer while on the ventral side the 
longitudinal muscular layer is about twice as thick as the tranverse muscular layer. 
This refers to the anterior somites. To this there is however an exception in somites 
viii and ix where on the ventral side in the vicinity of the spermathecal pores the 
transverse layer is thicker than the longitudinal layer. The transverse layer tapers 
down towards the spermathecal pores, but this thickening is found only in the imme- 
diate vicinity of the spermatheca. In the clitellar somites the relative development of 
the muscular layer is very different. Here the inner or longitudinal muscular layer 
is enormously thickened laterally in somites xvii and xviii or in the vicinity of the 
male pores (figs. 37, 38, 40, 41), while in the anterior part of the clitellum the longi- 
tudinal layer is only thickened ventrally, between the inner couples of sete it here 
being at least twice as wide as it is dorsally (fig. 39). 
Clitellum offers many points of interest. It has already been stated that this 
organ is incomplete, that is, not simultaneously developed on the dorsal and ventral 
sides. A section through an immature specimen shows (fig. 38) that the clitellar 
glandular layer is developed only between the seta, that is, from seta 4 ventrally to 
seta 4, while dorsally there is no trace of such cells. As regards the nature of these 
cells it is to be remarked that they are unusually small or rather thin compared to the 
larger and thicker cells of the dorsal part of the clitellum in the anterior somites of 
that organ. These latter cells offer nothing in particular of interest, resembling those 
of other genera of the family as far as I can make out. Unfortunately most of the 
specimens were immature and only two possessed clitellum, but these two had unavoid- 
ably not been treated, and had contracted to such very great extent that the finer 
structure of the clitellum had been hopelessly lost. From eross and longitudinal see- 
tions made it was, however, evident that the clitellar glandular cells, which constitute the 
clitellum, do not extend ventrally further than to sets 1, thus leaving the ventral space 
