E. T. CRESSON, JR. 107 



MYDAID^. 

 Etyphus towusendi Will. 



Numerous specimens of both sexes from Alamogordo, N. Mex. 

 (Viereck and Rehn). 



From this lot of well-preserved specimens I make the following 

 notes, which will also serve to distinguish the sexes. 



The pile of the male is much thicker than that of the female, and 

 in some places longer ; that of the thoracic dorsum n)ore appressed 

 and formed into four longitudinal stripes by a narrow bare black 

 median vitta, which extends from the anterior margin to quite some 

 distance from the scutellum, and also by two lateral ones, extending 

 from the humeri to the scutellum. The lateral pollinose spots be- 

 hind the humeri are sometimes indistinct, but in every case is more 

 distinct in the female than in the male ; the dorsum of the female is 

 also marked with two other fainter median pollinose stripes. The 

 pleurae of both sexes have, in addition to those of the sterno- and 

 mesopleurse, similar silvery spots on the hypopleurre and on the 

 rufous anterior lateral angles of the first abdominal segment. The 

 abdomen of the male opaque, at least not polished as in the female, 

 except the yellow posterior margins, and these bands are narrower 

 and that of the first segment more whitish than those of the female ; 

 the last segment shorter than the preceding. The legs of both sexes 

 sometimes brownish, especially the femora ; the hind tibiae of the 

 male with a distinct apical spine, at the base of which are one or 

 two stout bristles ; of the female, in place of the spine is a tubercle, 

 on which are three or four stout bristles. The wing veins of both 

 sexes are sometimes brownish, especially towards the anterior mar- 

 gin. Otherwise they agree with the typical description in Trans. 

 Kans. Acad, of Sci., xv, 58. 



9Iydas abdominalis Adams. 



A male and female, Florence, Arizona (Beiderman). 



illydas cletpis O. S. 



One female, Carr Canyon, Arizona (Skinner). 



Ulydas liiteipennis Lw. 



One male and female, Alamogordo, N. Mex (Viereck and Rehn). 



I make mention here of a male from Round Mt., Texas, closely 



allied to Mydas dives, but the abdomen is opaque-black, with only a 



TKANS. AM. KNT. SOC. XXXIII. APRIL, 1907. 



