10 Prof. J. C. Schiddte on the Structure of 
and to distend gradually the piece which les between them, 
until it is cut through by the cutting edges which glide clipping’ 
ast each other. In harmony with this structure of the mouth 
is the slender form of the body, the thin antenne, and the well- 
developed swimming-feet ; and it cannot be doubted, therefore, 
that Cirolane are purely carnivorous. The testimony of dif- 
ferent authors goes in the same direction. Thus we find in 
Strém’s physical and topographical description of the district 
of Séndmér, in Norway, a description of a ‘‘ Fish-Bear,” which 
must be a Cirolana (C. borealis in all probability), and which, 
he says, ‘“creeps into the fishes through the anus and eats the 
flesh of the fish from the inside, so that, if it only has time, 
it may eat the whole of the fish.” The author of this paper 
asked Professor Kroyer, the celebrated and experienced con- 
noisseur of Crustacea and Fishes, whether he remembered any 
fact confirming the conclusions as to the mode of living of Ciro- 
lanes which are suggested by the structure of their mouth; and 
Professor Kroyer then related that once, near the shores of Nor- 
way, not far from Throndhjem, he caught a large codfish which 
teemed with Cirolana borealis. The latter had eaten out such 
large cavities in the flesh that there was little left of the fish 
except skin and bones. In the hurry to secure this rich harvest 
Professor Kroyer tried to help himself by keeping some of the 
parasites in his closed hand, but they bit him so ferociously 
that he was obliged to let-them go at once. 
8. The third type is that of Serolides,of which Serolis Orbig- 
nyana, M.-K., may serve as an example. The stem of the 
mandibles (fig. 2,2) forms a very large, flat, oblique, quadrangle 
placed in a slanting position, and is evidently almost exclu- 
sively destined to give room for the insertion of the flexors, as 
the palpus rises from the exterior and posterior corners. The 
outer lobe has a similar shape, but is somewhat pinched off from 
the stem in the place where the large labrum begins to cover 
it in front ; there is no grinder, and the prehensile part is thick 
and slightly’ spoon-shaped, the apex broadly truncate, with 
thick rounded edge ; the inner margins of the mandibular lobes 
on the right and left sides meet each other accurately, but do 
not cross so as to cover each other: The inner lobe is small, 
divided into two lobules, which are attached to the outer lobe 
close under its prehensile part. On the right mandible both 
lobules are very small, soft, bipartite ; but on the left mandible 
the foremost lobule is much increased in size, thickly chitinized, 
_ and resembles the prehensile part of the outer lobe by its clumsy, 
rounded transverse edge. The mandibular palpus is long, 
slender, the two first joints fitting into a shallow groove run- 
ning along the outer margin of the stem and continued between 
