THE CANADIAN ENTOMOLOGIST. 239 



ensuing 1 discovered that a fine, robust specimen which I had taken from 

 decaying hickory the day previous had its left elytron .25 mm. shorter than 

 its right, this time the difference being much less, but still noticeable. I 

 then examined fifteen other specimens of this species in my collection, with 

 the following result : One with left elytron .25 mm. shorter than right; 

 one with left .20 mm. shorter than right; one with left shorter than right, 

 but the difference hardly appreciable ; one (small specimen) with right 

 .20 mm. shorter than left; and one in which the right was so slightly less 

 than the left that the difference could scarcely be seen. The remaining ten 

 showed no appreciable differences in this respect. So of seventeen speci- 

 mens examined, seven had the elytra unequal in length in a considerable 

 degree, one being especially prominent thereby. And it is noticeable that 

 in five of the seven specimens it was the left elytron that was the shorter, 

 these also being the cases in which the inequality was most prominent. I 

 believe all of my specimens, with one exception, were taken from their 

 cells in the wood, as they are found after having assumed the imago. I 

 have no doubt that if others would examine the specimens of this species 

 in their collections, many more such examples would be found which have 

 been overlooked. It would be interesting to know the result of such 

 examinations. It is probable that the elytra, being organs not of strictly 

 primary value to the insect — elytral invariability in this direction not being 

 absolutely essential when within certain limits — have thus been permitted 

 to vary without the variations being struck out by natural selection. I 

 have not observed this elytral inequality in any other Coleoptera as yet. 

 A form of this species, which is less robust, I occasionally find ; it is 

 slightly narrower in proportion and more delicately marked, but upon 

 sending specimens of the two to Dr. Horn, he informs me that they do not 

 differ appreciably, but are both oculatus. 



CORRESPONDENCE. 



NOTE ON THE HABITAT OF XYLORYCTES SATYRUS. 



Dear Sir : Mr. W. F. Robinson, of Bridgeton, N. J., sent, Oct. 28, 

 1884, a specimen of this beetle, with the remark that it is being dug up 

 around the roots of trees there in abundance by his school boys. The 

 collections here contain it not farther to the north than Pennsylvania. Not 



