Biological Papers. 187 



dots are often present. The species is a little more slender 

 and less robust than the sciitellaris varieties. 



On damp ground, in freshly irrigated alfalfa and corn-fields, 

 nigrocsenilea was quite common. It varied from green or 

 brassy-green to deep blue, or even black. It is a rather wary 

 species in bright sunshine, but on cloudy days could be found 

 running amongst the alfalfa. Along the narrow ditch that 

 carried the artesian water 16-punctata was frequent, but was 

 far outnumbered by hsemorrhagica. The latter grew more and 

 more abundant each day after August 1, until by the middle 

 of the month the damp, level ground covered with salt-grass 

 fairly swarmed with them. One could by sweeping his net 

 a few times over the top of the grass as he walked get enough 

 of the "red-ended" fellows to half fill a cyanide bottle. They 

 were nearly all dull black, though an occasional small one had 

 bright cupreous head and thorax, pleura, suture and legs, re- 

 sembling 16-punctata except for the markings, the sinuate 

 median band being constantly preserved. Under cow-chips on 

 the same damp soil several Tetracha Carolina were found. 



One of the collectors, while searching for Cardbiclse. along 

 the creek, hit upon a colony of the tiny Cicinclela aiizonensis, 

 at the base of a high and steep east bank of the creek. Further 

 search revealed another colony on a similar strip of bank. 

 When frequent visits to these colonies had nearly exhausted 

 them, a large colony was found in a distant part of the valley, 

 where the grass was short and sparse, and a number of de- 

 pressions caused by washing water after heavy rains left a 

 series of low, sloping banks, in the shelter and on the sides 

 of which the insects gathered. A few days later specimens 

 were found along irrigating ditches with lemniscata, though 

 ordinarily the two species were not found together. 



Arizonensis flies less readily than lemniscata, but is never- 

 theless quick in its movements. At first sight it somewhat 

 resembles celeripes. It is the smallest cicindelid of our 

 fauna, and probably the smallest in the world, being yet 

 smaller than lemniscata or celeripes. The markings consist of 

 apical lunule and median band, often reduced to a dot and, 

 rarely, even lacking. I can see little to separate it from the 

 Mexican viridisticta, since Bates's description of the latter 

 says "median marginal dot and very narrow apical lunule 

 white." I should at least place it as a variety of viridisticta. 



In certain limited areas in dry arroyos entering the valley 



