INSECUTOR INSCITI;^ MENSTRUUS 121 



Eggs obtained from captive females are long, slenderly 

 spindle-shaped, shining black, laid singly. 



Aedes aldrichi Dyar & Knab. 



This is the smallest Aedes known to me. While varying in 

 size, as all mosquitoes do, the average is small and often 

 minute. When biting, and the proboscis is driven far down, 

 the little insect tips up behind v^nd sometimes loses hold with 

 all its legs, suspended by the proboscis. The species inhabits 

 the river bottoms strictly, never straying far from the edge of 

 the timber. It is a close ally of idaho'ensis, but smaller, the 

 wing-scales all dark. The mesonotum has the two dorsal 

 brown lines narrow and separated, the anterior angles gray. 

 Certain intergrades occur, as noted above, but not in the 

 typical dense forested areas. 



A mount was prepared from a male taken in the timber with 

 numerous females of typical aldrichi, at Big Timber, July 13, 

 ini7. The genitalia (see Plate II) have the apical lobe of the 

 sidepiece well rounded off and bulbous, continued narrowly 

 basally, but not reaching basal lobe, clothed with small, sparse, 

 nearly straight setae; basal lobe expanded, tubercular, a mod- 

 erately stout spine arising from the inner (ventral) margin, 

 without long setae, the setae on the inner margin of the lobe 

 becoming dense, but not much longer than elsewhere ; filament 

 of harpago angularly expanded near the middle. 



The genitalia are, therefore, much as in idaho'ensis and 

 spencerii, differing in the reduction of long setae which accom- 

 pany the spine of the basal lobe in those species. 



