Pvn H,i I'UitlS

24 CRANIID.E.
** Hingeless.
Family II. CRANI'EME, (Cramadce) King.
Body circular : arms spiralty coiled, and not supported by
any shelly process or septum : attachment formed by the ad-
hesion of the lower valve, or part of it, to other substances.
Shell circular or subquadrangular : upper
valve conical or
cap-shaped: lower valve flat: muscular scars remarkably
strong and conspicuous.
Our seas contain at present one only of this hingeless
from all
group of Brachiopoda, which is distinguishable
the preceding kinds by the upper valve being conical
and the lower valve flat and attached, as well as in
neither valve being perforated. The shell is opened by
the action of the adjustor or protractor muscles; and
r this takes place only to a very limited extent. Throu
^
the Discinida? there appears to be a passage to Anomia,
both of which have a byssal peduncle issuing out of a
hole or slit in the lower valve for attachment to other
substances.
Genus I. CRANIA* Retz. PL I. f. 3.
As the family contains but this single genus, it is un-
necessary to recapitulate
the characters.
1. Crania ano'malaI-, Miiller.
Patella anomala
F.&H mala, Mull. Zool. Dan. Prodr. p. 237, no. 2870. C. anomala,
ii. p. 366, pi. lvi. f. 7, 8 ; (animal) pi. U. f. 2, as C. Norvegica.
Body of a milk-white colour, tinged with yellow or brown :
mantle very thin : arms thick and cirri
fleshy
rather nume-
;
rous, stiff, and rather long.
* From a fancied resemblance of the inside of the lower valve to the
front of a human skull,
f Irregular.