12 



SUPPLE MEN! TO PSYCHE. 



[May 1899. 



antennae and tarsi palei-; thorax and elvtra 

 iisLiallj covered witii a peculiar incrustation 

 (or exudation?).* 



Head differing in sculpture according to 

 sex, usually retracted into the thorax to 

 beyond the eyes. Thorax about as long as 

 wide at the middle; front margin greatly 

 arcuate and fringed with short, dense, yellow 

 hairs, anterior and posterior angles rounded, 

 sides arcuate, base nearly straight; disk at 

 middle with a longitudinal, tuberculated area 

 which, commencing usually some distance 

 behind the front margin of the thorax, be- 

 comes narrower toward the base, more and 

 more abruptedly elevated above the lateral 

 parts of the thoracic disk, and finally extends 

 beyond the base as a triangular, hood-like 

 projection over the scutellum t; sides and 

 inflexed flanks of thorax without distinct 

 sculpture. 



Elytra about ij times longer than tlie 

 thora.x at middle, punctate-striate, the striae 

 feebly impressed, punctures large ; interstices 

 narrow, convex, very finely uniseriately 

 punctured, each with a row of long, erect or 

 suberect long hairs, sutural interval gradually 

 becoming deeper behind; declivity' steep, 

 convex at the sides, sutural interval deeply 

 and broadly sulcate and limited externally 



*This incrustation is always present in fully matured 

 specimens and completely conceals the sculpture of the 

 elytra, except that a few of the longer hairs always remain 

 visible; on the thorax the tubercles of the median elevated 

 area are never covered, fn the more immature specimens 

 the incrustation m less dense, and the above description 

 of thoracic and elytral sculpture has been taken from such 

 specimens. Upon immersion in chloroform the incrusta- 

 tion is dissolved, and the surface of the insect appears to 

 be shining with thoracic and elytral sculpture much more 

 pronounced. Dr. J. B. Smith writes me that the elytral 

 structure indicates the possibility of excretory pores on the 

 surface. 



t The amount of individual variation, as exhibited in a 

 long series of specimens, regarding the various features of 

 tins remarkable structure of the thorax is very great, and 

 hardly two specimens can be found whicli precisely agree 

 in all structural details. The variations refer more especi- 

 ally to the extent of the tuberculated area, the degree of its 

 elevation, and to the form and size of the post-basal pro- 

 longation. 



b_v the third interval which becomes carini- 

 form and bears a row of five tubercles; fifth 

 interval also with some tubercles; the suture 

 itself being elevated at the bottom of the 

 sulcus. 



(J. — Front broadly and slightly concave, 

 feebiy pubescent, not distinctly punctate; 

 cl vpeus armed with a broad and long horn- 

 like process, usually as long as or longer 

 (very rarely shorter or much shorter) than 

 the thorax and which is composed of two 

 nearly cylindrical rods which are laterally 

 connate and of equal width fro in the base to 

 near the tip. The anterior and posterior 

 sides of the horn are shining and more or 

 less distinctly tuberculate, the lateral margins 

 are densely tuberculate and apparently 

 irregularly serrate and furnished with a 

 fringe of inoderately long hairs. Some 

 distance froin the tip, each rod is angularly 

 contracted laterally, and only the inner half 

 of each is prolonged into a shining, cylin- 

 drical prong-like process averaging about one- 

 eighth the length of the horn. The prongs 

 are distinctly separated from each other, and 

 the separation often extends more or less 

 deeply into the apical portion of the horn. 

 The outer truncature at the base of the 

 prongs is usually inerm, but in all immature 

 specimens, and often also in mature speci- 

 mens, it is furnished with a spine-like, 

 pointed process, as long or longer than the 

 prongs. In some specimens this process is 

 dissolved into two or more stiff setae. J 



$ — Head unarmed, feebly conve.\, indis- 

 tinctly punctured, covered with short, not 

 dense, yellowish pubescence; front with a 

 sinall, shallow impression which is smoother 

 than the surrounding space. 

 Length, 1.7-2.2 mm. 



Locality, Tucson, Arizona; types, 



X In the living specimens the horn is carried straight 

 forward ; in the dead mature specimens, the horn is more 

 or less vertical, while in all immature specimens it it 

 recurved back over the thorax. 



