316 
Transactions of the Society. 
Instead of the large square ventriculus, the caeca of which are mere 
shallow projecting corners, which we find in U. Krameri, the present 
species has the ventriculus considerably smaller and longer in shape, 
and the caeca ( cse ) which arise from the corners are very long and 
important ; probably no two specimens exactly agree, but all are 
sufficiently similar to be immediately identified by any one knowing 
the organs, even if he were not told the species. The hind pair of caeca 
are the wider, and are of nearly equal width throughout ; where they 
arise from the posterior corners of the ventriculus they run outward 
and backward until they are opposite the middle of the colon, they 
then turn sharply inward and backward and terminate about opposite 
the posterior end of the colon, which organ they thus almost surround. 
The two caeca at the anterior corners bifurcate as in Winkler’s species, 
but in G. formicarise the two branches are very unequal ; the posterior 
branch is directed transversely across the body, and is practically a 
continuation of the proximal portion of the caecum before the branching. 
At its distal end this caecum is suddenly enlarged so as to form a great 
irregular lobe which has somewhat the shape of a human foot turned 
backwards ; this lobe not only widens greatly superficially, but also 
becomes suddenly thicker dorso-ventrally than the remainder of the 
caecum. The anterior branch is the thinner, and does not enlarge at 
its distal end ; it is directed at first forward, then curves slightly 
outward, and lastly more strongly inward ; it and its fellow on the 
opposite side of the body practically nearly surround the brain. Instead 
of the five small anterior caeca found in U. Krameri two only are 
present in G. formicarise. Winkler does not mention any in his 
species. Almost the whole of the ventriculus and its caeca is 
decidedly, but irregularly, scalloped, i. e. divided up into minute 
shallow lobes or corrugations. 
The Reproductive Organs. 
The female genital organs differ so little from the usual type in 
TJropoda, e. g. Uropoda Krameri , that it is not, I think, worth saying 
anything about them here, except as regards the perigynium, or inner, 
membranous, genital plate. This organ seems to vary in form and 
construction in every species ; that of G. formicarive is shown at 
pi. VII. fig. 10, as seen from below; viewed from that .direction, the 
oval space at the anterior end is concave, and the keyhole-shaped 
portion in the centre is elevated ; the row of spines directed inward 
from the edge of this portion is on the surface of the organ furthest 
from the eye (the true upper surface) and is only seen in conse- 
quence of the transparency of the parts. 
The male reproductive organs show considerably more difference 
from the type of V . Krameri than the female do. Five sacs or 
organs exist in addition to the central chamber, but as the fifth shows 
signs of being formed from two paired organs the number fairly agrees 
