Mar. iSgo ] FaLL : Ox AMERICAN SPECIES OF ACM.tODERA. IT 



narrowed from base to apex, side margin narrow, inferior behind ; punctures on the 

 disk rather tine, separated by more than their own diameters on the average, coarser 

 and more closely placed laterally ; impressions moderate, side margin narrowly yellow 

 in basal three fourths. Elytra with numerous yellow spots of varying size and shape 

 irregularly dispersed ; base equal in width to the prothorax, gradually narrowed from 

 base to apex, striw moderate, impressed at sides and apex, intervals fiat, each with a 

 single series of fine punctures. Beneath clothed with rather sparse grayi.sh hairs. 

 Prosternum feebly trisinuate in front ; abdomen finely evenly not closely punctate, 

 last ventral w-ith large apical plate, the free edge thin and very broadly rounded. 

 Length, 9-9.5 mm., .36-. 38 inch. 



Habitat : Arizona (Tucson). 



Described from two specimens collected and communicated by 

 Mr. 'NMckham. Serena resembles both macra and elaiisa quite closely. 

 As compared with niaci-a the thoracic margin is narrow and not visible 

 throughout from above, the form is less arcuate when viewed in profile, 

 the markings are more broken, and the apical ventral plate which is 

 nearly wanting in maera is here strongly developed. From c/aitsa it 

 may be separated by the more sparsely punctured thorax, and the 

 thoracic margin becoming inferior behind as is usual. 



A. tuta Horn, Trans. Am. Ent. Soc, VII, p. 11, PI. I, Fig. 11. 



I have seen but four specimens of this species and these present no 

 variation from the description and figure given by Horn. The pros- 

 ternum is feebly trisinuate, the apical ventral plate very narrow, nearly 

 truncate with thin free edge. Length, 8-9.5 mm., .32-. 38 inch. 



Habitat : Utah and desert portions of California (Death Valley). 



A. hepburnii Lee, Trans. Am. Phil. Soc, 1859, p. 254. 



A species which there is no danger of mistaking for any other in 

 this grou]j, but which might easily be confused with connexa, acuta 

 and labyrinthica of the following group. The prosternum while not at 

 all strongly trisinuate is sufficiently constant so to warrant its present 

 position. The thorax varies very little in form, is never wider than 

 the elytra, and is narrowed from base to apex, while in acuta, etc., 

 the thorax is oftenest widest a little in front of the base, and frequently 

 more or less distinctly wider than the elytra. Again, in these species 

 the thoracic spot is rarely present and the side margin of the elytra 

 beneath the humerus is always black in part ; in hepburnii the thoracic 

 spot is absent in only three of the forty-five specimens before me, and 

 the elytral margin at the humerus is entirely yellow. The apical 

 ventral plate is narrow, the free edge thin and broadly evenly rounded. 

 Length, 8.7-12 mm., .35-. 48 inch. 



