184 Karz WILHELM GENTEE, 
those conditions, although it may occur in many other places. 
Whether the relations may justly be called mutualistic, so that each 
member of the community would have chiefly one function such as 
defense, locomotion, procuring food, scavenging, etc., only future 
careful study can reveal. As I have already said, I should regard 
the whole little world rather as a life-community, a biocoenosis, 
than as a group of parasites, symbiontes or messmates on and with 
the hermit-crab. 
Name of the American species. 
My specimens from the American Atlantic shore not only agree 
with the descriptions of Alcippe lampas Hanc., as given by Hancock, 
Darwin and AurtvisLıus, but the study of the details and especially 
of the sections and the comparison with BERNDTS paper and drawings 
has shown the full identity of the species. 
The anima lin sida. 
The peculiar slits on the inside of the shell which lead into 
the borings of the animal have been described and figured by the 
various authors who have written on Alcıppe. The largest ones are 
about 3mm in length, rounded on one end, tapering into a point 
on the other. The edge of the slit has a small dull whitish seam 
standing out against the light bluish and pearly shell which forms 
the sharp edge of the actual slit. This seam is filled in calcareous 
matter (Fig. 1c). About 2/3 of the slit are occupied by the two 
lips of the mantle whose rows of pointed chitinous teeth (Fig. 7) 
rest against it. In the living animal these lips (Fig. 1a) are pink, 
while the area between their tapering ends (6) appears dark 
brownish-red. The pointed end of the slit which is usually slightly 
curved (d), is again filled in and consists of fine sand granules and 
detritus held together by a secretion (?). It is somewhat variable 
in colour and often appears banded as in the figure where a light 
yellowish band runs across a dark brownish area. The pinkish 
“fan-shaped spot” (e), the area where the disk of the animal shines 
through, has been too often described to need further mention. It 
can be seen usually only in the older and larger specimens and 
even there it is often quite indistinct. The whitish striae are often 
indistinct or absent. It is hardly necessary to mention here once 
more that these striae and the white dots or holes (the dots being 
holes filled in with calcareous matter) are not due to burrowing 
