' REPORT ON THE PYCNOGONIDA. - 135 
In the first place, however, | wish to draw special attention to the fact that with regard 
to Nynuphon brevicaudatum, Miers, this rule admits of an exception. JI examined a species 
with large genital pores and swollen thighs, and provided with egg-masses on the ovi- 
gerous legs. On investigating transverse sections of the thighs, I soon saw that this 
specimen was a female. So far as I know, this is the first time that an exception to 
this rule has been observed. In the second place, I wish in a few words to discuss 
-the circumstance that, although eight different species of the genus Colossendeis were 
collected (together represented by thirty-one specimens, and four specimens of Colos- 
sendeis proboscidea, Sab. (sp.), trawled north of Scotland during the cruise of the 
“ Knight Errant ”), none of these are provided with eggs. The number of males, however, 
is very restricted: there is only one male Colossendeis leptorhynchws among nine speci- 
mens, there is one male Colossendeis gigas among six specimens, one male Colossendeis 
megalonyx among seven, and, finally, one male Colossendeis brevipes. On the other hand 
it is possible that the genus Colossendeis is an exception to the rule, and that the males 
in this genus may not have the gallantry to nurse their babies as the males of. the species 
of other genera are accustomed to do. For, comparing the ovigerous legs of the males 
with those of the females, a distinct difference is almost always easily observed: those of 
the males are a great deal stouter, the fifth joimt is as a rule swollen towards the 
extremity, or furnished with a distinct knob, &c.; but im the ovigerous legs of the 
males of the species of Colossendezs, these differences in form and size are never observed. 
So it is quite possible that they deal differently with their eggs from the species of 
other genera. 
’ The species provided with eggs are: Mymphon hamatum, Hoek ; N. eae Hoek ; 
nies Hoek; N. brevicollum, Hoek; N. brachyrhynchus, Hoek; N. ieee 
datum, Miers : and Ascorh ynchus minutus, Hoek. Of the latter species there are in 
all two specimens, and of these one bears eggs. But the development of these eggs is 
in its last stage, so that I was only able to ascertain the form of the larve. The eggs of 
this species are extremely small, and at the same time numerous. 
It consequently happened that my embryological researches were limited to the genus 
Nymphon ; in so far not unfavourable, as yet almost nothing has been published on the 
embryology of this genus. 
Full-grown males of the genus Nymphon bear the eggs on the fourth and fifth joints 
of the ovigerous leg, or only on the fifth joint; the curious foliaceous appendages occur 
on the sixth to the tenth joints of the leg, and have nothing to-do with the egg-bearing 
function of the leg. Yet it is possible that they may be of some use in seizing the eggs 
when just laid, but, on the other hand it must be observed, that in the genera where 
these appendages occur, the ovigerous legs of the females are furnished with them as 
well as those of the males. 
The eggs are soldered together and form in the species of Ny ymphon I spied! and 
