ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
569 
New Genera of Earthworms from Western Tropical Africa.* — 
Mr. F. E. Beddard describes Millsonia (AT. rubens , and M. nigra sp. n.) 
and Nannodrilus (AT. africanus sp. n.) from Lagos. Both genera are 
Cryptodrilid, and so belong to a family which is not known to be well 
represented on the African continent. N. africanus seems to be exceed- 
ingly common. 
Anatomy and Development of some Earthworms.! — Prof. A. G. 
Bourne describes two new Perichaetidae, one of which he calls Mahbenus 
imperatrix and the other “ Pericliseta ” pellucida , though he feels sure it 
is not a true Perichseta. 
He has some notes on the development of setae, and points out that 
those which first appear are embryonic, and that they are succeeded by 
permanent setae; his notes on the development of the nephridia deal 
chiefly with the stages that have a special bearing on the so-called 
plectonephric condition ; he is of opinion that this condition must be 
regarded as very doubtful, and Beddard’s figures in confirmation are 
severely criticised. Prof. Bourne states that, in spite of repeated and 
most careful search, he has never been able to see any connection be- 
tween one nephridium and another in the adult. 
Moniligaster. J — Prof. A. G. Bourne gives a detailed account of 
M, grandis , and has notes on other species of the genus. The author 
now finds himself able to offer further generalizations with regard to the 
vascular system of earthworms. He is able to recognize : (1) arteries which 
carry blood from the main trunks towards capillary networks ; these 
arise from the main tissues, and then repeatedly subdivide ; (2) veins 
which carry blood from capillary networks to main trunks ; these are 
formed by the repeated junction of smaller vessels, and finally open as 
single large vessels into a main trunk ; ( 3 ) veins which, like the verte- 
brate portal veins, carry blood from one capillary network to another ; 
these are vessels or networks of vessels, the branches of which all 
repeatedly subdivide until they become capillaries, and these are spoken 
of as a portal' system. 
The most important distinction which the author finds in the vascular 
system of worms lies in the presence or absence of this portal system. 
When it is present there are no intestinal arteries, wdien it is absent 
they are present. There is no portal system in Moniligaster or Lumbricus , 
while it has been found in all the Perichaetidae examined, and is 
doubtless present in a number of other genera. 
The character which appears to be of next importance is the presence 
or absence of a subneural trunk, and it may or may not coexist with a 
portal system. 
The resemblances of the gonads of Moniligaster to those of various 
lower Oligochaeta is very striking ; the testes belong to segment ix. and 
the ovaries to segment xi. ; there are no rudiments of gonads in any 
other segment. 
Prof. Bourne discusses, on the basis of his own experience, the value 
of various characters for systematic purposes ; colour has a certain 
* Proc. Zool. Soc. Lond., 1894, pp. 379-90 (3 figs.), 
f Quart. Joum. Micr. Sci., xxxvi. (1894) pp. 11-33 (4 pis.). 
i Tom. cit., pp. 307-84 (7 pis.). 
