126 



From Mr. Pott's experiments, of which a more extended ab- 

 stract can be found in the Jaliresbericht flir Agriculturchemie 

 for 1875 and 1876, Bd. ii, p. 119-121, it appears that the evo- 

 lution of carbonic dioxide, for hke weights and times, is greatest 

 in aves, less in mammalia, still less in insecta and batrachia, and 

 least in vermes and raollusca. 



In a house-mouse experimented upon, the same author found 

 the amoimt of carbonic dioxide exhaled varied when the animal 

 was kept in different colored lights, being greater in colored 

 light than in white light, and the greatest in green or yellow 

 light. A series of extended experiments upon the respiration 

 of insects would be a valuable addition to entomological knowl- 

 edge. (Jan. 11, 1878.') 



Stridulation of Colkoptera. Is it worth wliile to note in Psyche 

 the two following cases of stridulation ? I would be glad if other persons 

 having the opj^ortunity would observe the noises made by Coleojjtera, and 

 the movements by Avhieh they are produced. 



Passahis cornuiux makes a very loud stridulation by rubbing the acute 

 edge of the ventral segments against the inner edge of the elytra. Luca- 

 nus, on the contrary, is entirely mute. 



Prionus irevicornis stridulates by rubbing the rough surface of the inner 

 side of the hind thighs, near the distal end, against the outer edge of the 

 epipleurse, i. e., against the lateral margin of the elytra. The movement of 

 the legs is alternate and the sound is made while the leg moves downward. 



J. L. Le Colli e. 



Elytra of Dytiscus and Acilius. On page 436 of Packard's 

 " Guide to the Study of Insects," is a singular error, namely: — 



" The males of these two genera [Dytiscus and Acilius] often have the 

 elytra deeply furrowed while those of the iemales are smootli." 



The reverse of this is the general fact. The elytra of the males are smooth 

 and those of the females are furrowed. This arrangement is for the pur- 

 pose of enabling the males to get a good foothold. One does now and then 

 get hold of a smooth female, and it would be interesting to know if such 

 females are fertile. W. V. Andrews. 



Mode of Advent of Anthrenus scropiiuluriae. I have noticed 

 the new "carpet beetle," AtUlireuus scropJntlariae, in considerable numbers 

 for the past two years mingled with A. I'arius, among the dried skeletons 

 of Peabody Museum. As a large number of these skeletons have been 

 brought from England, I do not doubt but that the beetles were in this case 

 originally from thence, especially as they thus cling to their previous habit 

 of feeding upon dried meat. S. W. Willislon, New Haven, Conn. 



Correction. In no. 45, of Psyche, v. 2, p, 101, lines 13 and 14, for 

 Haldeman's read Leidy's. 



