142 



SEA-SHORE LIFE 



The Channelled Whelk, fSycotypiis canaliculaius J has no knoh-like 

 protuberances, but there is quite a deep channel at the suture of 



the spire. Also in the chan- 

 nelled whelk the shell is covered 

 with a rough, hairy-looking 

 skin whereas the surface of the 

 shell of the KnoblDcd Whelk is 

 smooth. 



These animals prey upon 

 other mollusks and are very 

 destructive to clams and oys- 

 ters. The mouth is at the ex- 

 m^ £«fV"^f/>ii, 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. 



The egg cocoons of our 

 whelks are often seen cast up 

 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. 



Fig. joi, 



Right: KNOBBED WHELK. 

 Left: CHANNELLED WHELK. 



Belotv: Egg cocoons of the Chan- 

 nelled Whelk. 



