DERMACENTOR VENUSTUS N. SP. 47 



Specimens come from various places in the West; Olympia, Ya- 

 kima, Klikitat Valley, and Grand Coulee, Wash. ; Fort Collins and 

 Boulder, Colo. ; Pecos and Las Cruces, N. Mex. ; Bozeman, Mont. ; 

 Bridger Basin, Utah; Soldier, Idaho, and Texas (on sheep). 



This species is quite common in the Northwest. It has been in- 

 cluded in D. occidentalis by Neumann, but was separated out by 

 Doctor Marx in manuscript under the name I have adopted. It is 

 larger than D. occidentalism with more red and less white in the color- 

 ing, and differs in many minor points of structure, as size of porose 

 areas, size of hind coxse in male, etc. This is the species supposed 

 to be concerned in the transmission of spotted fever in Montana. 



Dermacentor occidentalis Neumann. (PL X, fig. 9.) 



Male. — Eed-brown, with many waxy-white markings, often Avith a 

 waxy bloom, sometimes almost wholly white, but there is red-brown 

 near the eyes, on the festoons, and several submedian spots ; moreover, 

 the white is broken by the many red-brown punctures ; legs pale red- 

 dish brown, marked with white above. Capitulum (PL VIII, fig. 1) 

 rather narrow, and the hind angles prolonged into very prominent 

 spines ; palpi very short, not as long as the width of the capitulum ; 

 dorsum not much more than one and one-half times as long as broad, 

 with many punctures, but mostly small ; lateral furrows distinct and 

 long, twelve indented lines behind. Legs of moderate size, tarsus IV 

 (PL VIII, fig. 1) with two very distinct teeth below and oi;e less 

 jirominent, teeth on other joints distinct; coxa? (PL VIII, fig. 2) 

 armed as usual; coxa? IV about one and one-half times as wide at base 

 as long. Stigmal plate (PL VIII, fig. 2) elongate, with a broad 

 turned-up tip, almost truncate; large granulations on the main part, 

 small ones on the tip. 



Length of male, 8 to •>.;■) mm. 



Female. — Shield red-brown, mostly covered with white, red-brown 

 near eyes and in the middle region, and the white broken up by the 

 many brown dots at punctures ; capitulum and legs red-brown, latter 

 Avhite at tips of joints, and generally paler above than below; abdo- 

 men dark red-brown. Capitulum (PL VIII, fig. 1) rather small, 

 the hind angles prominent, and the jjorosa areas very small and rather 

 close together. Shield (PL VIII, fig. 1) al)out as broad as long, 

 broadest before middle, and rather pointed behind, with many small 

 punctures and some larger, but not nearly as many large ones as in D. 

 'paruma'peTtus. Legs rather small, coxse armed as usual. Stigmal 

 plate (PL VIII, fig. 2) with a broad dorsal prolongation, with large 

 granulations in the main part, and minute ones on the prolongation. 



Length of female shield, 1.5 mm. 



