38 THE NAUTILUS. : 
The existence of mollusks in water pipes is no new thing, though 
it is always interesting, and this is the first instance I have heard of 
in which any of the Plewroceride have such a habitat. M. Locard 
found 44 species belonging to 15 genera in the water-mains of Paris,’ 
and that they possessed certain peculiarities, no doubt the result of 
their environment. These were a diminution in size and decrease 
of coloration on account, perhaps, of the want of light; a more 
slender form, as this would make the least resistance to currents and 
enable the mollusks to cling more securely to the pipes. The speci- 
mens of Pleurocera sent by Mr. Lewis did not specially differ from 
those in the Museum Collection from Davenport, but, as the species 
had only been noticed at Hannibal a few years, it is probable that 
there has not sufficient time elapsed in its new environment to pro- 
duce any important changes. 
Many other cases of mollusks living in water pipes are known, 
notably that of Dreissensia polymorpha, introduced into England 
from the Aralo-Caspian region, and it has proven a serious nuisance 
in the mains of London, Birmingham and Manchester. 
MARINE SHELLS OF PUGET SOUND. 
By Mrs. Marie Drake. From the Transactions of Isaac Lea Conchological Chapter 
of the Agassiz Association for 1894. 
I have a Glycimeris generosa Gld. which I got from Dr. Pomeroy 
of Vashon Is. It weighed 7} lbs. when alive, and was dug from a 
depth of three feet. Its length is 72 inches, width 4% inches. Its 
longest circumference is 134 inches. It gapes widely at both ends ; 
rarely meets when alive. Its edges are covered with a yellowish- 
brown epidermis. The pallial sinus, though not very deep, is from 
} inch to 2 inch wide. Its distinet concentric grooves or lines are 
slightly irregular. The valves of this shell are strongly bulging. 
This shell is commonly called “ Goe-duck,” because it is so deep a 
burrower. The Indians esteem this shell-fish a great delicacy, and 
ornament their houses and yards with the shells. It is highly es- 
teemed as an article of food, though quite difficult to obtain; one is 
said to furnish food for a whole family. Star-fish are also found by 
the hundreds at low tide on the mud flats, and of every hue—bright 
scarlet, peacock-blue, sea-green and paler tints. 
1See NAUTILUS, Sept., 1894, p. 59. 
