180 
MARINE INVERTEBRATES 
pharynx, when protruded, is very large and long, and appears too 
large for the worm. The proboscis has four hook-like jaws. 
Glycera mec- 
kelii, with 
pharynx 
everted. 
These worms burrow rapidly and disappear almost 
instantly into the mud or sand. 
Genus Glycera 
G. americana. Color red or purple; has branched 
gills on upper side of parapodia. Found from South Caro- 
lina to Cape Cod on sandy and muddy shores and flats 
near low-water mark. 
G. dibranchiata. Has a simple gill on both sides of the 
parapodia; about eight inches long and one quarter of an 
inch wide in the middle; proboscis one inch long and wider 
than the body on the upper end. Abundant from New 
Jersey to Cape Cod. 
ORDER SEDENTARIA 
THE TUBICOLOUS WORMS 
Many of this order construct tubes in which they 
live permanently. Some species of both Sedentaria 
and Hrrantia have habits pertaining to the other. 
These worms are without a protrusible pharynx and 
without jaws. The body is usually divided into two 
or three sections by segments and appendages of dif- 
ferent forms. They have hair-sete on a limited 
number of segments only, varying with the species; 
the remaining segments have uncini, or hooked comb- 
like rows of sete, which are very small, but often 
crowded in bunches. Uncini exist also on segments 
having hair-sete. Parapodia’ are often lacking on 
the posterior parts and are usually without cirri. 
The gills are usually confined to the anterior end and 
are sometimes represented by tentacles around the 
head. The different species have characteristic tubes, 
formed by mucus secreted by epidermal glands. 
Sometimes the mucus hardens, making a parchment- 
like tube; again it cements together grains of sand, 
or bits of shell, seaweeds, ete. Some species secrete 
