162 ZOOLOGY, 
near the mouth. The umbrella is gradually withdrawn into 
the mouth, so that eventually only a crown of short tooth- 
like projections surrounds the mouth. Finally the whole 
umbrella is swallowed, the arms at the end of the body dis- 
appearing, while the end of the intestine projects far out 
rom the body behind the mouth. By this time the Phoro- 
nis form is clearly indicated, the body being long and slen- 
der and the mouth surrounded by a crown of short tentacles, 
the end of the intestine being entirely withdrawn within the 
body. These changes are rapidly effected. The larva ot 
Echiurus is formed on the Annelid type. 
In Phascolosoma cementarium (Quatrefages), the body is 
much shorter than in P. Goul- 
dii ; the worm lives in compara- 
tively deep water (10 to 50 fath- 
oms), in dead, deserted shells, 
building out the aperture by a 
conical tube of sand. In Stpun- 
culus (Syrinx) the tentacles are 
fringed or lobed. It does not 
occur in American waters. 
In Echiurus the intestine ends 
at the end of the body, and there 
is acircle of bristles at the pos- 
terior end, while Bonellia differs 
in having an enormous proboscis, 
and only a few bristles near the 
head. In Bonellia viridis Rol. 
of the Mediterranean (Fig. 111), 
the proboscis is deeply forked ; 
the intestine is very long, convo- 
Fig. 111.—Bonellia viridis; the luted, and into the cloaca empty 
proboscis coiled several times. p, two excretory organs. ‘The ovary 
fore end of the proboscis; 8, 8’, fur- . ‘ . ; 
row in the proboscis ; ii siestize is a cord-like organ, which in the 
choi on the anterior end of the dy posterior part of the body is fast- 
gestive canal); 7 -Sduo—atier ened to the intestine. 
Lacaze-Duthiers; from Gegenbaur. = Ch toderma nitidulum Lovén 
occurs in 20-40 fathoms off the coast of Europe and 
Northern New England. The body is long, cylindrical, and 
