740 



GEOLOGICAL SURVEY OF THE TERRITORIES. 



ARACHNID A. 



Ixodes hovis Riley. (Packard, in First Report Peabody Academy of 

 Science, 18G9, Fig. GO, fully gorged individual, natural size, and an- 

 other empty, enlarged : Fig. G7, mouth-parts much enlarged.) 



A reddish coriaceous flattened species, 

 contracted just behind the middle; head 



Fig. 66. Fig. 67. 



IXODES BOVIS. 



with the body oblong oval, 

 short and broad, not spined 

 behind, with two deep, round 

 pits; palpi and beak together 

 unusucdly short; palpi long 

 and slender ; labium short 

 and broad, densely spined 

 beneath ; above, the mandi- 

 bles are smooth, with ter- 

 minal hooks ; thoracic shield 

 distinct, one-third longer 

 than Avide, smooth and pol- 

 ished, convex, with the ly- 

 rate mesial convexity very 

 distinct. The whole body 

 is si)arsely covered with mi- 

 nute hairs. Legs long and 

 slender, pale testaceous red ; 

 cox;e not spined. 

 Length of body, .15 of an 



IXODES, MOUTH-PARTS. 



inch ; width, .09 of an inch. 



This species, which occurs in great abundance at times on cattle in 

 the West, and Texas and Central America, was also detected by Mr. 

 Merriam on a porcupine, {EretMzon ejjixanthus,) August 10, 1872, at 

 Henry's Lake, Idaho Territory ; and on Lepus Bairdii, (No. 47,) col- 

 lected September 15, 1872, at Snake River, Wyoming Territory. 



Argas Americana^ n. sp. (Fig. 68.) 



Though our specimens are from Texas, (Belfrage,) yet this interesting 

 Fig. 68. genus, which has not been known before to 



inhabit America, is associated with Ixodes 

 hovis, having been received in a lot of 

 Ixodes taken from cattle. 



Body very flat and thin, oval, with the 

 head and mouth-parts concealed by the 

 overreaching dorsal portion of the body, 

 which is bent npward around the margin, 

 though the edge is not revolute. Body 

 above covered with very numerous little 

 round pits, large in the middle and becom- 

 ing smaller on the edge. There are two 

 large, conspicuous oval pits on middle of 

 the anterior third of body ; just in front of 

 the middle a transverse curved row of six 

 smaller pits, three on each side. Behind 

 are six prominent pits, three on each side. 

 On posterior third of- the body are rows of 

 these punctures radiating outward. The 

 edge of the body is roughly granulated. Margin of body beneath pitted 

 as above. Smooth between the legs and on the head. Palpi long and 

 slender when stretched out, not reaching the edge of bodj'. Legs large 



ARGAS AMERICANA. 



