3 I2 



CHARLES ZELENV. 



ends of the branchiae begin to appear and wave back and forth 

 around the mouth of the tube as if feeling for signs of danger. 

 In this position the animal usually remains for sev- 

 eral minutes often with nothing more than the ends 

 of the two longest branchiae projecting from the 

 tube. After satisfying itself in this manner the 

 animal pushes itself forward and expands the whole 

 branchial crown with comparative rapidity. After 

 the development of the functional operculum this 

 organ is pushed to one side and the branchial 

 ends are slightly projected around its margin 

 before the thrusting out of the whole branchial 

 The circlet takes place (see Fig. 3). The young ani- 

 mals, as well as the adults, are extremely sensitive 



3 



FIG. 3. (> 

 38. ) Hydroides 

 pectinata. 

 young serpulid 



has thrust out the 



ends of its bran- to the slightest mechanical jar, a very small shock 

 chiae preparatory being sufficient to keep them within their tubes 

 to the expansion for & considerab i e time . At Naples I was often 



of the whole bran- 

 chial circlet. greatly annoyed while attempting to make draw- 

 ings of the animals in an extended state to see them 



O 



jerk back into their tubes at the sound of a band starting to play 

 in the adjacent park. Under such conditions they "sulked" in 

 their tubes until the musical selection was finished. 



INDIANA UNIVERSITY, 

 January 7, 1905. 



