46 American Midland Naturalist Monograph No. 1 



Ornithodoros hermsi Wheeler, Herms and Meyer, 1935 



Plate 5, Figs. 17 and 18 



1935. Ornilhodorus hermsi Wheeler, Herms and Meyer, not intended to be the original 



May description but diagnostic differentiation is included, p. 1290-1292. 



1935. Ornithodorus hermsi Wheeler, full description, pp. 435-438. 

 July 



1936. Ornithodoros hermsi, Wheeler, Herms and Meyer: Brumpt, pp. 1206-1208. 

 Sexes similar; adults and nymphs similar. 



ADULTS 



Body. — Oval, wider behind, pointed anteriorly. The size of the female 

 given by Wheeler was 5.0 x 3.1, and of the male, 3.8 x 2.4. Average sizes of 

 numerous specimens in the Rocky Mountain Laboratory collections are, for 

 females, 4.85 x 3.01 and for males, 3.42 x 2.42. The largest female measures 

 5.37 x 3.24 and the largest male, 3.69 x 2.40. 



Mammillae. — Numerous and moderate in size with the individual mam- 

 millae elongated, not conical, with sinuous, radiating ridges on the sides; 

 longer axes longitudinal in the lateral area; and in the median areas with their 

 longer axes tending to be concentric around the discs or groups of discs; of 

 about equal size throughout on the dorsal surface, smaller in the median areas 

 than at the sides on the ventral surface. 



Hairs. — A few fine hairs usually visible. 

 Discs. — Definite, but shallow. 



Legs. — Surface of legs smooth, not micromammillated, and with a few 

 hairs present. Legs short and small. Length of tarsus I, 0.42; metatarsus, 0.3. 

 Tarsus IV, 0.48; metatarsus, 0.36. All tarsi without dorsal humps but with 

 mild subapical dorsal protuberances. 



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



Hood. — Well developed as an anterior projection above the capitulum 

 and continuous with the anterior extension of the dorsal body wall. 



Camerostome. — Deep posteriorly, shallow anteriorly. In fully fed speci- 

 mens the camerostome is scarcely visible. 



Cheeks. — Absent. 



Capitulum. — Basis capituli with the length and width about equal. Surface 

 irregular with interrupted transverse wrinkles and with a group of short hairs 

 on each side at the base. 



Palpi. — Surface smooth. Article 1 with a narrow, knifeedge flange extend- 

 ing over the base of the hypostome; articles 2, 3, and 4 fre>». 



Hypostome. — Length from 0.21 to 0.27. Denticles arranged 2 / 2 and lim- 

 ited to the distal one-third, about five in each file; denticles of all files of about 

 equal size. Apically notched and the corona having numerous very fine denti- 

 cles. Posthypostomal hairs long. 



