404 



BUREAU OF ANIMAL INDUSTRY. 



Fig. 73.— a portion of the skin of 

 Argas miniatus, showing the mar- 

 ginal line mm, with the quad- 

 rate structures. Greatly _ en- 

 larged. Original. 



conical, its distal extremity somewhat thicker than its proximal; tibia and protarsus 

 cylindrical; tarsus with suddenly attenuated distal extremity and with prominent 

 dorsal protuberance, giving it a hunch-backed appearance, especially on tarsus I; all 



articles except coxa with short pennate bristles, which 

 become longer near apex of tarsus. 



Male. — Attains 4 to 8 mm. long by 2.5 to 5 mm. 

 broad. Capitulum 480 to 500yu broad, 0.3 mm. long 

 from base of the palpi to tip of hypostome. Mandibles 

 0.9 mm. long, digit 75yu; free portion of stem 325>u; 

 swollen base 500// long and about 270// broad; similar 

 in details to A. reflexus. Hypostome somewhat in- 

 dented at apex and bearing on each half 4 small den- 

 ticles, arranged in transverse rows; then more proxi- 

 mally, 6 large denticles, arranged in two longitudinal 

 rows; finally some smaller denticles, broad but not 

 very salient, on three rows and descending two-thirds 

 the length of the hypostome. Palpi 540 to 580// long: 

 First article, 120 to 164//; second, 155 to 160// by 140// 

 broad; third, 112 to 140//; fourth, 125 to 145//, with 8 

 to 14 terminal stiff bristly hairs; all articles, especially 

 the second, bear stiff bristly hairs, most of which are 

 slightly pennate. Genital pore narrower than the 

 capitulum, 128 to 204// broad. 



Female. — Attains 11 mm. long by 8.5 mm. broad. 

 Capitulum attains 670// broad. Mandibles 1.04 mm. 

 long, digit 80//; stem 352//; swollen base, 598 by 320//. 

 Hypostome as in male. Palpi: First article, nearly 

 square, 160// long; second article, 196 by 128yf<; third, 160 by 112//; fourth, 160 by 

 96//; 8 to 9 short, stiff terminal hairs on the fourth article; hairs on surface of all 

 articles, especially the second. Genital pore broader than capitulum (960:670), 

 between coxse I and II. 



Hexapod embrijo measures 680 to 768// in length, exclusive of capitulum, and about 

 the same in breadth; the capitulum is slightly subterminal, but its appendage and a 

 slight portion of the base extend out prominently beyond the anterior margin of the 

 body. Dorsally and ventrally the cuticle is much wrinkled, the lines extending for 

 the greater part transversely; in the middle of the back there is a circular to oval 

 area without wrinkles. Dorsal and ventral surfaces, also the articles of legs and palpi, 

 are provided with pennate 

 hairs, the most prominent 

 being a ventral row near pos- 

 terior margin of body. Base 

 of capitulum (ventral view), 

 192// long by 208// broad an- 

 teriorly, 160// broad posteri- 

 orly. Hypostome 144// long, 

 distinctly composed of two 

 halves closely united in 

 median line, its tip provided 

 ventrally with several trans- 

 verse slightly irregular mi- 

 nute denticles; these are followed proximally by larger denticles arranged first in 

 three, then in two longitudinal rows, the teeth of the lateral (marginal) row being 

 strongest, seven in number, and extending to the base; inner row smaller, may also 

 extend to the base. Mandibles 304 to 334// long; digit 44//, inner apophysis biden- 



Fig. 74.— Tarsus I of adult Argas miniatus, showing two sense 

 organs on tuberosity. Greatly enlarged. Original. 



