BRITISH WELL-WORMS.
7
with two setae. Finally, after having considered one or two
points connected with the reproductive system, into which I need
not enter, Mr. Beddard concludes as follows :—"All arguments,
therefore, appear to me to point to the conclusion that Phreoryctes
is, in respect of its reproductive organs, the most primitive type.
There is no type, in fact, in my opinion, which has such
good claims to occupy a low (i.e., archaic or early) position
among the Oligochaeta as Phreoryctes. It will be remembered
also that this genus is one which was placed by Lankester in a
position intermediate between the 'Limicolae' (or aquatic
worms) and the 'Terricolae' (or earthworms) of Claparede ; and
it does, undoubtedly, combine the characters of these two groups.
It is also a form which, as regards habitat, is on the border line
between the two divisions; it lives both in the water and on the
land. I look upon Phreoryctes as representing more than any
other existing form, the common type whence the Megadrili
(Earthworms or Terricolae) and the Microdrili (Waterworms,
aquatic annelids, or Limicolae) have been derived."
Should further investigation confirm this judgment we see
at once how valuable is the discovery in Great Britain of a new
species of this curious and interesting genus.
§ Michaelsen's Researches.
In 1898, Dr. Michaelsen, of Hamburg, published in the
Zoologischen Jahrbüchern a valuable article entitled "Beitrage
zur Kenntniss der Oligochäten," the first part of which (pp. 105-
118) is devoted to a study of "Phreoryctes gordioides (Hartmann),
und seine synonymie." He calls attention to the fact that in the
early part of this century Hartmanii gave some account of a
worm which he called Lumbricus gordioides, and which had pre-
viously been confused with Gordius. After various historical
allusions the author adds :—
" Zu Phreoryctes gordioides muss ferner de von dem irischen
Gelehrten Rev. H. Friend aufgestellte Art Dichaeta curvisetosa (Friend
on 'The Scientific Study of Worms' in the The Naturalist, 1896,
p. 79) gezogen werden. So spärlich die Angaben über diese Art sind—
dem Alitor derselben lag nur ein einziges, jugeadliches Exemplar vor
—so lassen sie doch die Phreoryctes Natur des Wurms erkennen. 'The
worm—which is aquatic in habit—is about four inches in length, and
composed of some 250 segments, the first of which, like all the rest,
contained two setae only. Modified setae occur on segments n to 14;
the head (prostomium) is long and narrow, and the brain ganglion
apparently circular in front.' Auch der Speciesname 'curvisetosa '