76 Journal New York Entomological Society. [Vol. xvi. 



beetles' surface are thoroughly indurated and equally adapted to re- 

 pelling the mandibular onslaught. There seems to be only one way 

 out of the difficulty thus presented by the simultaneous development 

 of these protective and alluring adaptations in the Cremastochili, and 

 that is to regard these beetles as degenerate symphiles, forms that were 

 once true guests, with more highly developed trichomes and living on 

 much more amicable terms with their hosts. In having fallen from 

 this estate they resemble certain species of Paussus that have been 

 studied by Escherich. Cremastochilus has, in fact, all the ear-marks 

 of a very senile genus. Its species, like somber hypochondriacs, are 

 condemned by an ancient instinct to dwell in the busy emmet world 

 without participating in its splendid activities. The weariness of a 

 long and eventful evolution seems to lurk in their hard, pock-marked 

 integument and rheumatic joints. Having outlived a period of abject 

 sycophancy, they would, perhaps, return to a free and independent 

 life, were it not that their brains have been enfeebled by too many 

 generations of parasitism. 



Nothing is known concerning the development of Cremastochilus. 

 The larval and pupal stages are passed, in all probability, in the ant- 

 nests, and from what has been learned of allied forms, like Cetonia, 

 we should expect to find the larva in the vegetable debris of the nest. 

 July 22, 1903, while examining a nest of Formica microgyna in 

 Williams Canon near Manitou, Colorado, I found besides a number 

 of adult C. 7vheeleri, a single Cetoniine larva, which may be that of 

 this beetle. It was buried in the vegetable debris and on being 

 exposed by a stroke of my trowel, was at once seized and injured by 

 the irate ants. It resembles rather closely the larva of Osnioderma 

 eremita figured by Schiodte (De Metamorphosi Eleutheratorum Obser- 

 vationes, VIII, 1874, Tab. XI, Fig. 1). If it is the larva of C. 

 wheeleri it is only about two thirds grown. 



The mating of Cratiastochilus sometimes takes place in the ant- 

 nests. At any rate I have seen pairs of C. castaneoz and canaliailatus 

 in copula, in the outer galleries of F. schaufussi nests in April. Lieb- 

 eck (1899) took the mating sexes of C. leucostictus Burm., which are 



American species Harris (A Treatise on Some of the Insects Injurious to Vegetation, 

 1862, p. 42) says: " They have the odor of Russian leather, and give this out so 

 powerfully that their presence can be detected by the scent alone, at the distance 

 of two or three yards from the place of their retreat." This scent is retained for 

 years in cabinet specimens. 



