MONILIGASTER GRANDIS, A. G. B. 369 
investigation, it has been most forcibly borne in upon me from 
time to time that in the specimens presenting intermixed cha- 
racters there was something wrong with generative apparatus, 
e.g. ova not found separated from the ovary and the ovisacs in a 
particularly shrivelled condition, while in more typical speci- 
mens at the same time of year the ovisacs are full of ripen- 
ing ova. 
I have given what I consider to be the typical distinctive 
characters of the three species in the above diagnoses, and I 
now give, in the annexed table, a few particulars of some speci- 
mens of what I should call variations of M. sapphirinaoides 
among worms taken at random from one and the same locality. 
To carry the subject further it would be necessary to do this 
for each species in groups from various localities, but this 
would prolong this paper beyond reasonable limits, and I should 
like to do this at some future time on a really large scale. 
Specimens 8 and 9 at any rate are immature, and they may 
pass as young M. sapphirinaoides; the sete are rathersmall, 
but the setz, like the exoskeleton of an arthropod, are shed at 
intervals and replaced by larger ones; the seta has not a per- 
manent growth, and the full-grown embryonic seta of one of 
these species is 0'1 mm. long. The gizzard is far forward in 
them and, indeed, in all these specimens, but the normal posi- 
tion for M. sapphirinaoides has been determined by the 
examination of a much greater number. The condition of the 
ovaries and the spermathece in 4, 8, and 9 is due, I think, to 
immaturity. 
Specimen 2 is what I should call a hybrid between M. 
sapphirinaoides and M. robusta,—the sete, gizzard, and 
copulatory pouches resemble the latter species ; the size, colour- 
ing (as in all the specimens), relative distance between the seta 
rows are as in the former. 
Specimen 1 also resembles a M. sapphirinaoides, but its 
seta gaps have the peculiar arrangement characteristic of M. 
robusta. 
The nephridiopores are not mentioned above ; by the time I 
could have made certain of the position of all of them the worm 
