48 CALIFORNIA ACADEMY OF SCIENCES. 
tubular network, which only gradually fuses itself into one duet with numerous 
branching ductules, while in Lumbricus the single duct continues through the differ- 
ent lobes and in recurring winds around itself. The tubules in Argilophilus em- 
brace the two tubes but cease after leaving the first fold. The muscular duct which 
is so prominent in Lumbricus is not represented in Argilophilus, but is replaced by an 
elongation of the single wide tube corresponding to the “ wide tube of the 3d lobe” in 
Lumbricus. 
Compared again with the nephridium of Deltania, we find that the principal 
difference consists in the absence of the urinary bladder and the collar at the ne- 
phridio-pore as well as in the absence of a eweal bladder. The irregular or alternate 
locations of the nephridio-pores distinguish Argilophilus and Plutellus from all other 
earthworms, as far as known. 
Alimentary canal (fig. 87 to 92). The buccal cavity is, as has been stated, 
greatly eversible, and generally remains everted after the worm is dead. The 
pharyne is only developed superiorly though there is a slight thickening of the lower 
wall of the buceal cavity at the junction with the cesophagus, at which place numer- 
ous muscles are seen to connect with the lower part of the body-wall. The pharynx 
is as usual furnished with numerous salivary glands (fig. 86, s/. g/.), extending from 
the vicinity of the brain to the posterior part of somite iy, the most posterior glandular 
mass being the largest (fig. 86). The various glandular lobes offer some characteristics, 
which if carefully noted and compared may be found to be constant enough to serve 
as species characteristics. 
The Qsophagus begins in iii and occupies somites iii, iv and y, (fig. 86, A. w.) 
forming first a narrow tube, which widens out, and rising upwards connects with a 
very large gizzard (gz.). This gizzard occupies in reality only somite vi, but its great 
length causes it to push far backward to such an extent that it actually occupies the 
space covered by viii and sometimes by ix. The gizzard is compressed from above, 
but widened laterally which makes it appear very much larger when viewed from 
above than when seen in vertical section. It connects posteriorly, in vii, with a very 
long narrow tubular intestine, which extends to somite xii, but which in somites xiii 
to xv is strongly nipped by the septa and considerably enlarged (fig. 86, s,) without, 
however, being strictly sacculated. 
The sacculated intestine proper, however, begins first in xvi, and is much wider 
than the other part of the alimentary canal. The structure of the pharynx offers 
nothing of unusual interest. The wall of the gizzard contains the usual layers, but they 
are poor in blood vessels. The longitudinal muscular layer is thickest, and on the 
widest part of the gizzard it is five or six times as thick as the epithelium, gradually 
diminishing in size anteriorly and posteriorly (figs. 86, 87, 88, 89). 
Pear-shaped or Chylus Chambers. Beginning immediately behind the gizzard, 
and extending throughout the tubular intestine, we find imbedded between the 
epithelial folds numerous pear-shaped organs of doubtful funetion. In pronouncing 
