74 ■ GEO. H. HORN, M. D. 



Occurs in Kansas and northern Texas. For a specimen of the 

 female which seems to be rare, I am indebted to Prof. F. H. Snow 

 of Kansas. 



P. cavifrons Lee, Proc. Aead. 1854, p. 222; Journ. Acad. 1856, p. 228.— 

 Clypeus truncate in front, margin moderately reflexed, angles not prominent. 

 Front flat coarsely punctured and with few, short, semi-erect hairs. Thorax with 

 very few erect hairs in front, surface sparsely clothed with scale-like hairs which 

 are denser in the median sulcus, lateral vittse indistinct. Elytra sparsely clothed 

 with scale-like hairs forming a subvittate appearance. Body beneath with moder- 

 ately long hairs, abdomen with elongate scales sparsely placed. Length .96 inch; 

 24 mm. 



Male. — As in the preceding species. 



Female. — Unknown. 



This species could be confounded with the preceding only. It has a 

 somewhat more robust facies and diflPers in the form of the clypeus and 

 the surface vestiture. 



My specimen was collected at Ehrenberg, Arizona ; those in Dr. 

 Leconte's cabinet are from an uncertain locality in the same Territory. 



P. deceniliiieata Say, Journ. Acad, iii, p. 246; Lee. loc. cit. 1856, p. 229. — 

 Clypeus trisinuate, sometimes feebly, the angles distinct. Vertex flat with few, 

 short, semi-erect hairs, densely scaly at the sides. Thorax with a few erect hairs 

 along the margin only, surface sparsely clothed with white scales, forming a denser 

 vitta in the median impression and on each side. Seutellum densely scaly. Elytra 

 scaly, the suture three nearly entire vittse and a short subhumeral line densely 

 clothed with white scales, the remainder of the surface sparsely clothed with scales 

 which are often yellowish. Pygidium rather densely clothed with narrow elongate 

 scales. Body beneath as in Hammondi. Length .96 — 1.44 inch ; 24 — 36 mm. 



Male.— Antennse as in Hammondi. Anterior tibite bidentate. Middle and pos- 

 terior tibise with one short spine a little below the middle. 



Female. — Anterior tibiae tridentate, middle and posterior each with two short 

 spines on the outer edge. Antennal club 5-lamellate, a little longer than half 

 tbe stem. 



Specimens occasionally occur in which the vittae are somewhat irregular 

 or interrupted. 



Occurs from Colorado westward to California. 



P. Ci'iiiita Lee, Journ. Aead. 1856, p. 2.30.— Very closely resembles the pre- 

 ceding sj)eeies and differs in having moderately long, erect hairs on both the head 

 and thorax. The latter has the usual scales replaced by very narrow scale-like 

 hairs, even the three vittpe can hardly be called scaly. On the elytra the scales 

 are also more liair-like while they form a style of ornamentation resembling that 

 of denemlineatn. Length .88 — 1.04 inch; 22 -26 mm. 

 Sexual characters as in decemhneata. 



This species appears to bear the same relation in the matter of vesti- 

 ture to the preceding that cavifrons does to Hamwondi. 



0(-curs in the Central ^^ alley of California. 



