Studies on Earthworms. - Journal of Cell Science

232 WILLIAM BLAXLAND BENHAM.
4) are wide apart. The nephridiopores are in a line with
seta 2, but only commence in somite xiv. The male pore
is in somite XVIII, in line with seta 1. There is an ellipsoidal
copulatory papilla in the ventral mid-line between somites xix
and xx, and another between xx and xxi. The oviduct opens
in somite xiv. There are two pairs of spermathecae in
somites vm and ix, each having a small spherical appendage;
their pores are on the anterior edge of the somite in line
with seta 1. The ciliated rosettes of the sperm duct
are in the somites preceding the seminal reservoirs, which lie
in somites xi and xn. There is a large prostate in somite
XVIII. There is no gizzard and no subneural blood-vessel.
Grube (30) has described, under the name Lumbricus
littor alis, a worm from Villafranca, which is probably another
species of Pontodrilus. This has three pairs of " copulatory
papillae," in line with setae 2, in somites xix, xx, and xxi.
In 1875 M. Perrier (32) described four species of Perichffita
from the Philippines, and one from Cochin China.
P. bicincta has only two somites in the clitellum.
P. biserialis has the usual three somites in the clitellum;
there is a ventral median and a lateral break on each side in
the ring of seta?, and the ventralmost seta on each side is
larger than the other setae of the somite. There are several
pairs of copulatory papillae behind the male pores.
P. luzonica has a similar arrangement of setae, but has
the clitellum on four somites (xiv to xvn).
P. coerulea also has the clitellum on three somites.
P. Juliana (from Saigon) has a continuous ring of setae
on each somite. It has four pairs of spermathecse.
Grube described (32A) an Earthworm from Rodriguez, and
named it Perichaeta rodericensis.
Lankester, in 1879, described an Acanthodrilus from Kerguelen
(33), A. kerguelenensis, in which the setae are
separated and form eight rows (but become paired in the genital
somites); the male pores are in somites xvn and xix; the spermathecse
are in somites vm and ix; the penial setae are notched.
The nephridia of this genus are here mentioned for the first time.