128 OILMAN A. DREW. 



near South Hapswell, Maine, in from ten to thitry feet of water, 

 by means of a fine wire dredge. Supposedly where conditions 

 are right for individuals to grow to a centimeter in length, larger 

 ones would thrive also. 



The usual position for undisturbed specimens is with the pos- 

 terior ends of the shells protruding just above the surface of the 

 mud. Sometimes specimens are found with several centimeters 

 of their shells protruding, but this is not very common. Again 

 all that indicates the presence of a specimen, may be the depres- 

 sion at the spot where the animal has disappeared. The most 

 conspicuous parts of a specimen in its normal position are the 

 siphons, the openings of which appear as nearly round apertures 

 surrounded by tentacles (Fig. 5). Close observation is necessary 

 to see such specimens, as the color of their siphons is almost 

 exactly the same as the bottom where they occur. 



Specimens that have their posterior ends protruding above the 

 surface of the mud seem to be more common where the water 

 has drained entirely away than where the flats are still covered 

 with water. Shells are not uncommon on the flats and shores, 

 but they are seldom found embedded in the position that the 

 animals occupy during life. These observations are of especial 

 interest in view of the fact that animals in aquaria quite uni- 

 versally push up out of the mud before they die. The heat of 

 the sun on the bare mud flats is probably disturbing an'd may 

 cause them to react in the same way they do before they die. 

 If animals react in nature as they do in aquaria, it is natural that 

 the shells of dead animals should be found on the surface. 



Specimens are not easily studied in their native places because 

 of ripples on the water and because the character of the bottom 

 makes it hard to approach closely without disturbing them. 

 Walking on the mud near them will cause them to withdraw 

 their siphons or disappear beneath the surface. It has accord- 

 ingly been more satisfactory to study specimens in aquaria that 

 contain several inches of sand or mud from the bottom from 

 which the specimens were obtained. The animals do not live 

 well in aquaria, even when supplied with running water, but for 

 several hours after they are collected, they remain very active 

 and seem to be quite normal. 



If a specimen is touched it will either withdraw its siphons anp 



