62 Mr. J. Wood-Mason on Scolopendrella. 
appear to be attached; and they therefore are posterior to the 
rudimentary legs. If a specimen be placed for a short time 
whole in a solution of hematoxylin, the everted mouths or the 
coagulated excreta collected upon these become deeply coloured 
by the reagent, so that the ventral surface of the animal is 
marked conspicuously with a double row ot large round black- 
violet spots. An accident unfortunately happened to the spe- 
cimen thus treated before I had had an opportunity of actually 
counting and noting down the number of openings that had been 
coloured; and I have been obliged to suggest that the round 
sclerites of the second, eleventh, and twelfth pairs of legs may 
be imperforate, though | fully believe that they are perforate 
like the rest. These openings possibly lead into glands 
which are homologous with the nephridia of Peripatus and 
with the glandular pouches of Machilis and Campodea; their 
exact morphological value is only to be determined by means 
of sections, which I hope shortly to have an opportunity of 
making. ‘They are no doubt the apertures mistaken by Ryder 
for the stigmata, and which are stated by Scudder to be big 
enough to admit the tips of the legs. 
Postembryonic Development.—Menge, according to Ryder’s 
synopsis of his paper, met with a young animal provided with 
only eleven pairs of legs, and concluded that it was the first 
pair which was wanting; I, on the contrary, have never 
tailed to recognize the first pair by its characters at any stage, 
and I am confident that it is one of those in possession of 
which the animal leaves the egg. Newport and Ryder both 
noticed ‘‘ specimens of different ages with nine, ten, eleven, 
and twelve pairs of legs.” I can confirm their observations, 
which prove that a pair of legs is added at each moult; and I 
have succeeded in making out the position of the germinal 
region. 
In larve provided, in addition to the three-jointed first pair 
of legs which properly belong to the head, with seven pairs of 
rudimentary and seven pairs of functional legs, nine terga (ex- 
clusive of those which respectively carry the pediform third 
cephalic and the caudal appendages) are present, or two more 
than the number of double pairs of feet. It is difficult, owing 
to the manner in which the terga seem to have been thrown 
out of correspondence with their double sterna, to determine 
with certainty which these apparently apodous terga are; but 
they appear to me to be the fourth and seventh (the fifth and 
eighth it the third gnathites are reckoned in with the ambu- 
latory legs) and the dorsal ares of the somites to which the 
fifth and sixth pairs of rudimentary feet belong. <A certain 
knowledge of this, as of many other points in the structure of 
