106 American Midland Naturalist Monograph No. 1 



Ornithodoros viguerasi Cooley and Kohls, 1941 

 Plate II, Fig. 48 



1941a. Ornithodoros viguerasi Cooley and Kohls, original description, pp. 396-399, 

 with figures. 



Nymphs and adults dissimilar; whether sexes are similar or dissimilar is 

 unknown. 



ADULT 



Body. — Sub-oval, broadest at about the middle, narrowly rounded behind, 

 and a little pointed in front. Broad anterior point bent ventrad where it meets 

 the anterior extensions of the supracoxal folds, from which it is separated by 

 a depressed line. Size 3.12 x 2.1. 



Mammillae. — Numerous and of various sizes and forms. Those in the 

 median dorsal area large, crowded, of irregular shapes, flattened on top and 

 each with a central pit which may bear a hair; those in the anterior marginal 

 areas on the dorsum much as in the median area but smaller and with hairs 

 more numerous; those in the dorsal posterior margin elongated, arranged 

 radially, and only slightly elevated. Venter with a transverse band just poster- 

 ior to coxae IV, extending from side to side, in which the mammillae are 

 unique among mammillae of all known species. This band extends over the 

 l?teral margins becoming visible from above and also has extensions on the 

 supracoxal folds and in the median area between the coxae. These mammillae 

 at the margins are elevated, columnar, about twice as high as their diameters, 

 ■convex on top and each with a single fine hair; height of the mammillae dimin- 

 ishing progressively from margins to the median area where they are only 

 slightly elevated and yet retain a sharp margin of the convex top. The surface 

 of the derm between these modified mammillae is finely and evenly pebbled. 



Discs. — Large, distinct, a little depressed and with their surfaces shining; 

 not apparent on the venter. 



Legs. — With numerous barbed hairs which are shorter and more barbed 

 on the dorsal surfaces, larger and less barbed on ventral surface. Surface shin- 

 ing and with transverse wrinkles. Subapical dorsal protuberances and dorsal 

 humps absent. Length of tarsus I, 0.42; metatarsus, 0.3. Length of tarsus IV, 

 0.50; metatarsus, 0.4. 



Coxae. — Coxae I and II a little separated; all others contiguous. 



Hood. — No well developed hood is present though the anterior projection 

 of the dorsal body wall is bent downward and resembles a hood. 



Cheeks. — Conical projections about as long as the diameter at the base 

 and bearing a few short, fine hairs. 



Capitulum. — Basis capituli with the surface irregular but shining; with a 

 median longitudinal elevation. Only the anterior portion of the basis capituli 

 is visible in the type female and it is not evident whether the capitulum is 



