409 
On a new genus of Ixodoidea. 
Origin. Description based on 1 f and 1 $ from a horse, 
Tolosa, Oaxaca, Mexico, collected by Mr A. Laughton, 1907. 
(Preserved in 70°/ o spirit.) 
Note. — Digit of $ similar to A. atrogenatum (Fig. 32). Digit of $ 
missing. Spiracle of g '5 mm., that of ’8 mm. long. Colour : dried 
for 48 hours the general coloration in the remains the same, the metallic 
spots appear a dull coppery colour. In the $ the metallic coloration also 
corresponds to the light portions of the scutum in Fig. 28. 
Amblyomnia atrogenatum n. sp. 
Figures 30 — 32. 
Male, L. 4*5 to 5 mm., W. 3*5 to 4*5 mm. Body (Fig. 30) short 
oval, narrower in front. Scutum entirely covered with golden me- 
tallic sheen (see Note) except cervical grooves and a narrow dark 
brown line on each antero-lateral border (hence “ atrogenatum ”) 
starting from scapulae, including the small yellow flat eyes, and 
ending at or before the spiracles; cervical grooves crescentic, convex 
outside ; lateral grooves complete but only commencing just in front 
Fig. 30. <? , A dorsal, B ventral aspects. 
of spiracles ; most specimens show three linear dark markings, one 
median posterior, two midway diverging in front. Venter pale, with 
dark brown anal ring and five well-marked chitinous plaques near 
posterior border; spiracles short comma-shaped. Capitulum : base 
triangular with a large golden patch dorsally, flanked by dark 
brown patches; posterior ridge straight; 1*2 to 1*6 mm. long; 
palps of medium length ; hypostome (Fig. 31) equal to palps in 
length, dentition 4|4 merging into 3|3. Legs of medium length, 
pale dorsally, but showing faint annulations and dark markings 
