106 Journal Xew York Entomological Society. [Vol. xix. 



the middle pair in swimming; the front legs play no part in this 

 method of progression, for they are extended forward on each side 

 of the head, ready to seize an object upon which to come to rest. 



In locomotion on land, however, the legs move in an entirely dif- 

 ferent manner from what they do in swimming. Bclostoma and Nepa 

 use all the legs in walking. In crawling, Bclostoma alternates the 

 movement of the hind legs, as well as the middle legs, but in swim- 

 ming each pair of these legs moves simultaneously. Brimley (i, p. 

 88) claims that Benacus griseus while crawling, moves the hing legs 

 together at first, "' and afterwards when he got used to the situation, 

 alternately . . . . " When Ranatra amcricana is taken out of the water 

 and is not thrown into the death feint it may, at first, give the 

 typical swimming movement, but later, the posterior pairs of legs 

 move as in Belostoma. 



Belostoma can occasionally be induced to take wing by a number 

 of diflferent methods. In one experiment fifteen of these bugs were 

 taken out of the water, which was at 19° C, and exposed for one 

 and a half hours to the temperature of the atmosphere at 21° to 23° 

 C, when two specimens made eager efforts to escape by flying against 

 the sides of the dish in which they were confined. While working 

 on the effect that sunlight may have on the duration of the death 

 feint, it was found that Bclostoma sometimes takes wing after com- 

 ing out of the inert state. A method which rarely fails to induce 

 Bclostoma or Ranatra to fly is to arouse the creature's phototactic 

 reactions by means of an artificial light. Although Ncpa is without 

 doubt able to fly, in no case have we succeeded in making it take 

 wing. 



Bibliography. 



1. Brimley, C. S., 1905. Ent. Neivs, XVI, p. 88. 



2. BuENO, J. R. DE LA ToRRE, 1903. A Day's Collecting in February. Can. 



Ent., XXXV, pp. 123-S. 



3. 1903. Notes on the Stridulation and Habits of Ranatra fusca Pal. 



B. Ibid., XXXV, pp. 235-7. 



4. 1903. Brief Notes Toward the Life-History of Pelocoris femorata, 



with a few Remarks on Habits. Journ. N. Y. Ent. Soc. XI, pp. i66- 



5. 1905. Notes on Hydrometra niaritinia Kirk. (^= lineata Say). Can. 



Ent., XXXVII, pp. 12-15. 



6. 1905. The Tonal Apparatus of Ranatra quadridentata Stal. Ibid., 



XXXVII, pp. 85-7. 



