Page:Tropical Diseases.djvu/288

GENERIC CLASSIFICATION OF TICKS

Rostrum terminal. Dorsal shield present. Sexual dimorphism marked	$\scriptstyle {\left.{\begin{matrix}\ \\\\\ \ \end{matrix}}\right\}\,}$	Family Ixodidæ	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \\\ \\\ \\\ \\\ \ \end{matrix}}\right.}$	Anal groove surrounding anus in front.	Prostriata Ixodinæ	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \ \end{matrix}}\right.}$	Inornate, without eyes and without festoons. Spiracles round or oval. Palps of variable form. Tarsi without spurs. Sexual dimorphism pronounced. In the ♂ the venter is covered by non-salient plates; one pregenital, one median, one anal, two adanal, and two epimeral plates. Parasitic on Ungulata, carnivora, rodents, marsupials (kangaroo), bats, and birds.	$\scriptstyle {\left.{\begin{matrix}\ \\\\\ \ \end{matrix}}\right\}\,}$	1. Genus Ixodes.
				Anal groove containing anus behind.	Metastriata	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \ \end{matrix}}\right.}$	(a) Brevirostrata. Rostrum short. Inornate, without eyes but with festoons. Usually with short conical palps, whose second articles project laterally. Small size and slightly chitinized. Sexual dimorphism slight. The ♂ shows no ventral plates or shields.	$\scriptstyle {\left.{\begin{matrix}\ \\\\\ \ \end{matrix}}\right\}\,}$	2. Genus Hæmaphysalis.
							Usually ornate, with eyes and festoons. Short, broad, or moderate palps, and basis capituli rectangular dorsally. Spiracles sub-oval or comma-shaped.	$\scriptstyle {\left.{\begin{matrix}\ \\\\\ \ \end{matrix}}\right\}\,}$	3. Genus Dermacentor.
							Inornate, with eyes and festoons. Short palps, with basis capituli hexagonal dorsally with prominent lateral angles. The ♂ resembles Rhipicephalus dorsally, Dermacentor ventrally. Spiracles sub-triangular or comma-shaped.	$\scriptstyle {\left.{\begin{matrix}\ \\\\\ \ \end{matrix}}\right\}\,}$	4. Genus Rhipicentor.
							Usually inornate, with eyes and festoons. Short palps, and basis capituli usually hexagonal dorsally. The ♂ possesses a pair of adanal shields and usually a pair of accessory adanal shields. Spiracles bluntly or elongate comma-shaped.	$\scriptstyle {\left.{\begin{matrix}\ \\\\\ \ \end{matrix}}\right\}\,}$	5. Genus. Rhipicephalus.
							Inornate, with eyes, but indistinct festoons. Short palps, and capitulum intermediate between that of Rhipicephalus and Boophilus. Highly chitinized. The ♀ with very small scutum. The ♂ with a median plate prolonged into two spines projecting beyond and to either side of the anus. Anal groove obsolete. Spiracles rounded or short, oval in both sexes.	$\scriptstyle {\left.{\begin{matrix}\ \\\\\ \ \end{matrix}}\right\}\,}$	6. Genus Margaropua.
							Inornate, with eyes, but indistinct festoons. Very short compressed palps ridged dorsally and laterally. Basis capituli hexagonal dorsally. Slightly chitinized. Unfed adults of small size. The ♀ with small scutum. The ♂ with adanal and accessory adanal shields. Spiracles rounded or oval in both sexes. No anal groove.	$\scriptstyle {\left.{\begin{matrix}\ \\\\\ \ \end{matrix}}\right\}\,}$	7. Genus Boophilus.
							(b) Longirostrata. Rostrum long. Ornamentation absent or present, at times confined to the legs; with eyes, with or without festoons. Long palps. Basis capituli subtriangular dorsally. The ♀ approaching Amblyomma. The ♂ with a pair of adanal shields, and with or without accessory adanal shields, and two posterior abdominal protrusions capped by chitinized points. Spiracles comma-shaped.	$\scriptstyle {\left.{\begin{matrix}\ \\\\\ \ \end{matrix}}\right\}\,}$	8. Genus Hyalomma.
							Generally ornate, with eyes and with festoons. Long palps, of which the second article is especially long. Basis capituli of variable form. The ♂ without adanal shields, but small ventral plaques are occasionally present close to the festoons. Spiracles subtriangular or comma shaped. Sub-genus Aponomma. Devoid of eyes, or in which the eyes are poorly developed. Body frequently very broad. Occur almost exclusively on reptilia.	$\scriptstyle {\left.{\begin{matrix}\ \\\\\ \ \end{matrix}}\right\}\,}$	9. Genus Amblyomma.
Rostrum concealed by overlapping cephalothorax. Dorsal shield absent. Sexual dimorphism slight.	$\scriptstyle {\left.{\begin{matrix}\ \\\\\ \ \end{matrix}}\right\}\,}$	Family Argasidæ	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \ \end{matrix}}\right.}$	Body usually flat with thin edges. Ventral grooves absent or very shallow. Eyes absent.					Genus Argas.
				Body with thick edges. Ventral grooves present. Eyes sometimes present.				$\scriptstyle {\left\{{\begin{matrix}\ \\\ \end{matrix}}\right.}$	Genus Ornithodoros.