MISCELLANEOUS. 325 



which then existed in the condition of a transparent and perma- 

 nent gas, mingled with the atmosphere, surrounding the earth, 

 and protecting it like a dome of glass. To this effect of carbonic 

 acid it is possible that other gases may have contributed. The 

 ozone, which is mingled with the oxygen set free from growing 

 plants, and the marsh gas, which is now evolved from decompos- 

 ing vegetation under conditions similar to those then presented by 

 the coal fields, may, by their great absorptive power, have very 

 well aided to maintain at the earth's surface that high temperature 

 the cause of which has been one of the enigmas of geology. 

 Montreal, August 1st, 1863. 



MISCELLANEOUS. 



THE CONFUSED MONOHAMMUS ! 

 To the Editor of the Canadian Naturalist. 



The longicorn described by me (Canadian Journal, 1st series, vol. 

 iii, p. 212) as Jtfonohammus titillator, Fab., was determined by 

 Mr. Ibbetson and myself from the best American Entomological 

 authority that could be obtained at the time. 



Mr. Billings states (Canadian Naturalist, vol. vii. p. 431), that 

 " M. confusor is the largest insect." I disagree with him, because the 

 longicorn family, and this genus especially, has its species of max- 

 imum and minimum lengths and breadths, a fact that cannot be 

 overlooked by a person collecting a number of each species. He 

 further says : " As neither Mr. Ibbetson nor myself mention M • 

 confusor, and as the original specimen on which the species M* 

 titillator was founded is an insect from the Southern States, it may 

 be that they have applied the name to our most common and 

 largest species." 



Fabricius may have procured his specimen from the South, 

 probably from the southern limit of pines ; but sine e his time Ame- 

 rican Entomological authority formed a boundary, north of which 

 our insect provinces are formed into zones ; through these we may 

 follow the species to the extreme north. Insects therefore, taken 

 north of Mexico are considered as belonging to the northern fauna ; 

 indeed, many forms mentioned by Linnseus and Fabricius as 

 having a southern habitat, are found commonly in the north. 

 What then is to prevent the appearance of M. titillator in Western 



