1894.] Abalone or Haliotis Shells of the Californian Coast. 853 
a rock, a slight blow upon the shell often causes the shell-fish 
to adhere more firmly to the rock and at the same time dis- 
charge jets of water out of every hole. When entirely at rest 
the abalone adheres to the rock and is as completely covered 
by his shell as a watch would be under an inverted saucer, 
excepting thatthe five or more holes in the shell admit the 
entrance and exit of water. 'The large muscular foot with its 
epipodial ridge bordered with cirri extends outside of the 
shell when the animal is gliding along. This foot is to all 
appearances only a muscular expansion of the body. The 
animal has no operculum or trap-door, as in most families of 
this class, as it is like the limpet in having no use for an 
opereulum.  Abalones have a short head and eye peduncles. 
The gills or branchia, intestines, etc., are all on the same side 
of the shell as the holes, and the * columellar margin is pro- 
duced into a flattened spiral plate," that forms a ridge suffi- 
ciently broad to protect all the digestive organs. The heart 
has two lateral auricles. The mantle is cleft at the row of 
holes extending thus “as far back asthe last open hole.” The 
odontophore or radula is large, and the variety and size of the 
teeth on this lingual ribbon can be seen without the aid of a 
microscope. A section of the odontophore makes one of the 
most attractive mounts furnished by the radula of molluses. 
Reference was made to the fact that sometimes old shells 
had only one or two holes open when the animal was very old; 
when such is the case the shell is usually covered with a 
growth of vegetation, worms, or other molluscs. Whole colo- 
nies of Serpulorbis attach themselves to one shell making a 
very heavy load for a shell-fish to carry, even one so muscular 
as the abalone. Although they do travel somewhat, it is not 
improbable that with age the animal becomes more and more 
sedentary until almost incapable of locomotion. An abalone 
brought from the Pacific, about 24 miles away, after it had 
shown very little appearance of life, crawled from a pail of 
sea water, eighteen inches in one night, where it was found 
dead in the morning. The abalone marks his passage by a 
5The ondontophore, sometimes called the **tongue" or “lingual ribbon" is set with 
rows of sharp siliceous teeth. In a large abalone it is about 3 inches in length. 
