Pvn H,i I'UitlS

ASTARTE. 313
upper tertiary strata up to the Red Crag, the variety
elliptica being the more usual form in glacial deposits.
This form has not been found south of Great Britain ;
but the variety hicrassata has a wide range in that
direction, throughout
the Mediterranean and Helles-
pont to the Canaries. Northward this species reaches
Iceland, Upper Norway, and the White Sea, as well as
North America (and the variety elliptica as far as Spitzbergen),
at depths varying from 3 to 160 fathoms. All
the other varieties which I have specified come from the
Hebrides and Shetland.
The animal is very inactive ;
and when buried in mud
the shell is often incrusted with a mineral coat like
tar. Specimens living in tenacious and fetid soil have
the beaks and umbonal area more or less eroded. Thev
are now and then distorted; and I found a large and
malformed pearl in one. The ribs are less numerous
and developed in southern examples of the typical form
than in those from more northern parts.
The inside is
sometimes of a lovely salmoncolour. In specimens
from the Northumberland coast and Skye the front
margin is plain
and the sides are crenulated. The
larger kinds of Asterias are said by M. Gay to prey upon
A. incrassata.
I have failed to separate intermediate forms from
either the typical species or the variety elliptica. They
may belong to one or the other. Particular specimens,
and indeed the bulk of them, may be readily distin-
guished ; but although it may not be agreeable to the
mere collector, whose object is to get as many species
as he can, I must regard the Crassina elliptica of Brown
as only a variety and northern form of this most incon-
stant species. I have never in the course of my dredging-
experience found them in company on the
p
same