142 SEA-SHORE LIFE 
The Channelled Whelk, (Sycotypus canaliculatus) has no knob-like 
protuberances, but there is quite a deep channel at the suture of 
the spire. Also in the chan- 
nelled whelk the shellis covered 
with a rough, hairy-looking 
skin whereas the surface of the 
shell of the Knobbed Whelk is 
smooth. 
These animals prey upon 
other mollusks and are very 
destructive to clams and oys- 
ters. The mouth is at the ex- 
tremity of a proboscis, and is 
armed with a ribbon-like 
tongue covered with rasping 
teeth. In eating, the end of 
the proboscis is applied to the 
victim’s body, and the flesh 
rasped off by vigorous sweeps 

of the ribbon-tongue. 
Fig. 101; Right: KNOBBED WHELK. The egg cocoons of our 
Left; CHANNEDLED Warts whelkseare often scen caste 
Below: Egg cocoons of the Chan- : ; ct I 
nelled Whelk. upon the beaches, and resemble 
a row of yellowish colored 
checkers fastened upon a cord. Each checker is in reality a tough, 
disk-shaped capsule containing about two dozen eggs or young 
whelks. According to Coues, when forming the capsules the female 
lies buried a few inches beneath the sand and remains stationary 
during the process. The string of capsules is slowly thrust upward, 
and when completed lies exposed upon the surface. The string 
begins as a simple thread, without capsules, and the first few cap- 
sules are small and imperfect but soon increase in size, being most 
perfect at the middle of the string. There is a thin spot at the mid- 
dle of the outer edge of each capsule and through this the young 
break their way. The capsules of the Knobbed Whelk are smooth 
sided disks, but their narrow edges are crossed by sharp ridges. 
Those of the Channelled Whelk are thinner with a thin, sharp outer 
edge, while the broad sides of the disks show radiating ridges. 
