292 
MR. A. D. MICHAEL ON THE LIEE-HISTORIES 
posterior and a pointed anterior end ; was compressed dorso- 
ventrally, particularly at the posterior margin ; and had a more 
or less plain sulcation round it, as though dividing cephalothorax 
from abdomen (in some specimens this was very marked). The 
mass had the general form of a Hypopus, but there -was not, in any 
instance, any trace of legs, mouth, or other external organs. In 
many instances the protoplasm appeared to be divided into large 
cells, like an egg in an early stage of segmentation ; in others the 
cell-division appeared to have gone further, the cells being much 
smaller and finer, particularly in the posterior portion of the 
creature, but some of the larger cells remaining ; in others, pre- 
sumably more advanced, the finer granulation was more uniform. 
The mass was always motionless, but in one instance I did 
find a living nymph within the case instead of the inert mass ; 
this of course was ready to emerge. The cases from which the 
occupant had emerged almost invariably contained the cast 
cuticle of the protoplasmic mass, which cuticle did not show a 
trace of legs, mouth, or any other organs. 
GrLTCIPHAGUS spinipes. 
At the end of 1885 I w r as at a farm-house for a short time, and 
thought it a favourable opportunity to renew the investigation. 
I found in the chaff-house, in the dust and chaff 1 , and also attached 
to the walls and beams, a number of cases which I at first 
supposed to be similar to those I had before dealt with : I soon, 
however, found that these were even more opaque than the former 
specimens, and that they were coarsely reticulated instead of 
being finely vermiform in markings ; the empty cases also opened 
differently, the posterior cuticle breaking away from the dorsal 
and lateral, and remaining attached to the ventral, so that the 
posterior end opened downward instead of upward, and was more 
torn ; the hinder part of the dorsal cuticle also w T as usually split 
along the median line and the two sides somewhat separated. It 
was therefore probable either that they were in a different stage 
from those observed in June and July of the same year, or that 
they were under different climatic or other conditions, or that 
they belonged to a different species of Acarns. I finally found 
that the last explanation was correct, and that these reticulated 
cases were those of G. spinipes. Between the 28th December, 
1885, and the 1st January, 1S8(3, I found a considerable number 
