AST ACE A. 
ILYANTUlDJi. 
THE WAVED MUZZLET. 
Peachia undata. 
Plate VIII. Fig. 4. 
Specific Character. Column cylindrical, short ; conchula cut into five 
shallow lobes ; tentacles crossed by dark wavy bands. 
Peachia undata. Gosse, Annals N. H. Ser. 3. i. 418. 
GENERAL DESCRIPTION. 
Fokm. 
Column. Cylindrical, rounded below, slightly fluted, about twice as 
long as the diameter of the disk ; terminating below in a central perforate 
depression, around which the skin is much puckered, and minutely cor- 
rugated. Surface wrinkled, both transversely and longitudinally, espe- 
cially when contracted. Margin distinctly angular, sometimes forming a 
very low parapet. 
IRsk. Smooth, flat, or rising with an even and very gentle elevation 
from the foot of the tentacles to the edge of the mouth ; marked with 
twelve radii forming so many fine lines. 
Tentacles. Twelve, in one circle, marginal ; thick and rounded at foot, 
tapering regularly to the tip, which is obtusely pointed ; transverse 
section sub-ovate, the diameter from side to side exceeding that from back 
to front. By irregular contraction, they sometimes become slender and 
cylindrical, often with the tip clubbed or knobbed. They are generally 
carried widely expanded horizontally, with the tips arching downwards, 
like a twelve-rayed star. 
Mouth. Descends abruptly from the disk 
with a sharp angle, but which can scarcely 
be called a lip, as it is not thickened. It 
is protrusile at the will of the animal, when 
ordinarily it embraces the exserted gonidial 
groove, and displays a number of plicae at 
its edge. 
Conchula. The groove is greatly de- 
veloped ; its edges are in contact until 
about one-sixth of an inch from the tip, 
where they separate, and turn over with a scroll-like expansion, the margin 
of which is cut into five shallow teeth, as follows : — one terminal and two 
CONCHULA OF P. UNDATA 
{magnified). 
