182 Kari WILHELM GENTHE, 
the subject to withdraw altogether. My notes will thus necessarily 
appear incomplete and fragmentary. 
Alcippe lampas Hanc. 
So far Alcippe has been described from the N.E. and S.E. 
shore of England, the W. shore of Sweden, from the island of Sylt 
and from the so-called “Rinne” near Heligoland. The animal has 
been found in cavities in the shells of marine snails, esp. Buccinum 
undatum, inhabited by hermit crabs. 
At Woods Holl, Mass, Alcippe is found in great quantities 
boring in shells of Natica (Lunatia) heros Avams and Neverita (Natica) 
duplicata Stimp. which are inhabited by hermit crabs and usually 
covered with hydractinians. Just as in the European specimens 
the animals are always found in the last whorl, sometimes a few 
only, sometimes a great many, and especially in the spindle. They 
are often so crowded together that only paper-thin partitions are 
left standing between the cavities (Fig. 3) and the animals not 
having room enough to spread and develop symmetrically become 
twisted and quite irregular in shape, but thin as the partitions may 
become, they always seem to keep the cavities separate. 
Shells which have been occupied by the crab apparently only 
a short time, to judge from the fresh appearance, and which show 
no, or only a slight, growth of the hydractinians shelter usually 
only a few and, moreover, only small specimens of Alcippe. But 
other shells are very interesting in so much as they form little 
worlds of their own and harbour little life-communities. The outside 
is covered with barnacles and a dense growth of hydractinians often 
to such an extent that except where the shell touches the ground 
and is dragged along, there is not a bit unoccupied. In the shell 
we find besides the hermit-crab a polyclad, Stylochus zebra, gliding 
smoothly and rapidly along on the walls, especially when disturbed, 
but keeping, by daylight at least, usually near the columella in the 
upper whorls. An annelid, Lepidonotus squamatus, is found in the 
same positions. Attached to the inner surface of the shell we often 
see Crepidula and almost always annelids living in their winding 
tubes, others tunelling the substance of the shell itself. _Alcıppe, 
often in large numbers, make their cavities and boring sponges 
(Vioa?) spread their dense meshwork through the substance of 
the shell. 
