June, 'o6j ENTOMOLOGICAL NEWS. 193 



Type No. 9629, U. S. Nat. Mus. 



One male, taken by C. B. Doyle, at an altitude of 2950 

 meters at Tierra Adentro, Central Cordillera, Dept. of Cauca, 

 Colombia, South America, headwaters of the Palo River, in 

 January, 1906. 



This interesting insect, which is named after the collector, 

 is easily distinguished from the other members of the genus by 

 the elongate form and especially by the coloration of the head. 



A Rock-boring Mite. 



BY NATHAN BANKS. 



In the fall of 1904, Prof. J. H. Comstock sent me some 

 pieces of rocks taken from a limestone cliff that is moistened 

 by the fall of water. The surface contained numerous small 

 cavities or pits of varying sizes. Most of them had a narrowed 

 orifice, and within each pit was found a mite, approximately 

 of the size of the pit. Although, of course, a mite of such 

 habits must be called " petrophagus " I have no idea that rock 

 forms any part of its diet. The surface of the stone to a short 

 depth is somewhat softened, doubtless by the action of the 

 water, and it is probable that in the minute holes and passages 

 of this softened area there is growing some tiny plant-organism 

 that forms the food of this cave-digging mite. From all 

 appearances the cavities are caused by the mite, and increase 

 in size with the growth of the acarian. Possibly the mite has 

 some secretion that aids in the destruction of the stone. 



Remarkable as are the habits of this mite, its structure, save 

 that it belongs to a rather peculiar genus, is not exceptional. 

 This habit is the necessary consequence of the conditions of its 

 existence, for if the mite should try to live free on the surface 

 of the rock it would be washed away by storms. To escape, 

 therefore, the ravages of the elements it takes to the cyclone 

 cellar. Migration must be performed over the surface of the 

 stone, but it is probable that the young issue at a season when 

 the stone is not subject to heavy storms. 



On microscopic examination the mite is seen to belong to 

 the family Oribatidee, or beetle-mites, and to the genus Scnlo- 

 vertcx of Michael. We have, at least, one other species of this 



