Mr. G. Hodge on the Development of a Species of Pycnogon. 37 
the sacs present a strong likeness to “ stunted branches” of the 
polypary, as if a shoot had been suddenly brought to an abrupt 
termination by an enlargement consequent upon its occupation 
by a young Pycnogon. This view of the case becomes more 
evident if we examine the annulated character of the sac, which 
will be found to agree closely with the same parts seen in the 
- polype, which are similarly annulated. It would therefore ap- 
pear as if the young Pycnogon occupied the place of the ordinary 
polype in the Coryne. The sacs are usually found on the lower 
portions of the stems branching out from the sides, as shown at 
fig. 6, though occasionally they were met with much higher up. 
The only manner in which I can account for their position on 
the lower portions of the stems is this: the young Pycnogons, 
judging from their growth and the circumstances under which 
they are found, must have gained access to their tenements at 
an early period of the year, when the Coryne was but small; and 
the higher branches would seem to be growths subsequent to 
the period at which larval forms abound, which have risen above 
the et of the parasitically infested shoots. 
I possess a female Phowichilidium, taken during the present 
year, at Lerwick, by the Rev. A. M. Norman, which has several 
germs or ova seated on the false feet: from an examination of 
this specimen I was so fortunate as to obtain a clear insight into 
some of the very early stages of the ova, which, so far as I can 
judge, throw much light upon the subsequent stages. 
Each sac or germ contains a large number of minute ova, 
which are attached to the investing membrane by four filament- 
ous appendages. These ova, in early stages, are globular (see 
fig. 1), and appear to consist of a number of granules enclosed 
in a transparent envelope, from whence proceed the filaments 
just alluded to. As these granules increase in size, they undergo 
a sort of segmentation, and put out six rounded lobes, four 
being at the precise spots from which the filaments are produced, 
while the remaining pair are larger, appearing between the two 
pairs, and rapidly increase into two prominent processes, which 
soon assume the form of foot-jaws (see figs. 2 & 3), and are each 
provided with a pair of “nippers.” The first four warts, two 
and two, continue their growth, increasing in length very con- 
siderably, and ultimately produce four legs, which, though un- 
jointed, are capable of considerable movement. From the tips 
of these legs the long filaments are seen to proceed ; and these 
have also considerably increased in dimensions, especially at their 
junction with the legs. Meanwhile the foot-jaws have also con- 
siderably enlarged, and by their outward growth have given 
place to another lobe or wart between them, which shortly 
assumes the form of a rostrum. And now we see a little Pyc- 
