68 



in the summer months after the strong south east winds. It also feeds 

 on small Crustaceae and Medusae, which it appears to catch, when 

 covered by the water of the incoming tide, by entrapping them by the 

 rapid motion of a muscular fold in the anterior region. This muscular 

 fold is also used rather like a shovel in burrowing. In crawling along 

 the sand the anterior lateral portions of the foot move together like 

 wings, and, as they are pushed back, the anterior and posterior pedal 

 tentacles are pushed into the sand. These tentacles then appear to 

 assist in obtaining a grip of the ground, so that the animal may push 

 itself along. They are not steering organs as has been suggested. When 

 picked up by the shell it does not immediately retract, unless the foot 

 or some protruded part is touched, but first attempts to remove the ob- 



Fig. 3. A section in anterior lateral region of foot, showing pedal tentacle and pore 

 leading into foot cavity. WP, water pore; FC, foot cavity; T, tentacle; EP, epi- 

 thelium; MUi, MU2, MUj, muscle layers. 



ject holding the shell. This it does by gritting the serrated operculum, 

 situated on the dorsal surface of the foot, against the object. At the same 

 time it endeavours to bite by means of the mandibles of the mouth. The 

 head tentacles are situated laterally just in front of the siphon. They 

 are sensitive but without eyes. The osphradium is large and pectinated. 

 Their sense of smell is well developed, as is evidenced by the fact that, 

 when feeding on the polypes of Physalia, they readily find them again, 

 even when waves wash them behind obstructions. 



