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RHIPICEPHALUS LONGICOXATUS Neumann, 1905.
DISTRIBUTION IN THE SUDAN
Bahr El Ghazal Province: Galual-Nyang Forest, lo ex €I'llS caffer aequinoctialis, 18 February 1953, H. Hoogstraai legit.
R. longicoxatus is an extremely rare tick from scattered localities #. East and Central Africa. The bulk of records referring to this species are from the arid Somalilands and coastal lowlands of East Africa, with a few savannah records from a circumscribed area in the interior of the continent.
CENTRAL AFRICA: FRENCH EQUATORIAL AFRICA (Rousselot 1953B).
FRENCH SOMALILAND, BRITISH SOMALILAND, KENYA (Hoogstraal 1953D). TANGANYIKA (Neumann 1905. Hoogstraal 1953D). Note: Recently while identifying specimens for British Museum (Natural History), another male R. longicoxatus with the following data has been encountered: Camel, Las # British Somaliland, 21 September 1936; B. F. Peck legit (with R. Pravus, Hyalomé dromedarii, H. rufipes, and H. truncatum).
?ITALIAN SOMALILAND: Figure 17 and 18 in Paoli (1916), reported as R. ecinictus, on the basis of two males, one from the ground and one from a camel, may refer to R. longicoxatus with the characteristic shape of the adanal shields, as IIIustrated, very slightly modified, or to R. £ersii. 7
Domestic animals: Camel, goat, and sheep (Hoogstraal 1953D). Note the two other records for camels above.
Wild animals: African buffalo (Sudan record above) and bushpig (Rousselot I.353B).
The East African records of R. longicoxatus give the impression that this is a Somali tick £####rather arid situations. The Sudan focus is in an area far removed but with a long, intense dry season. The fact that this tick also occurs in the more humid French Equatorial Africa is perplexing and indicates that we are still poorly acquainted with its biology. This appears to be a decidedly uncommon species.
Male: The scutum varies from 2.0 to 4.5 mm. in length, and from 2.0 to 3.1 mm. in width; it is widest at about midlength or slightly posterior of this level, and slightly convex, shiny, reddish brown. Cervical grooves are short and deep; marginal grooves are lacking but indicated by a row of large, deep punctations. Festoons are short and superficial. Scutal punctations are rare, large, distant, in irregular lines like those of R. s. simus; interstitial punctations are very few to numerous, very fine or almost obsolete. The illustrated distribution of scutal punctations is typical. Posteromedian and paramedian grooves are absent though it is possible that posterior depressions may develop after death and contraction of the specimen simulate these grooves. Eyes are flat, yellowish, large, marginal or almost marginal (see note below). The adanal shields are strongly punctate and triangular; the juncture of the lateral and pos
terior margins is subrectangular; the juncture of the posterior and inner margin forms a very slight, rounded protrusion; and the inner margin is posteriorly slightly convex and sinuous, anteriorly narrowing, and slightly concave. The accessory shields are short, not heavily thickened, and do not extend beyond the outer margin of the adanal shields. The basis capituli dorsally is about twice as wide as long and with at least two punctations, lateral margins widest at anterior third, cornua broadly rounded. The hypostome has 3/3 dentition in files of nine to eleven denticles. Palpi are slightly longer than wide, flat dorsally. Coxa I has a distinct, dorsally-projecting process.
Note: In the very anterior position of the eyes, the specimen described and illustrated by Rousselot (1953B) conforms more closely to the original description of R. longicoxatus than do our specimens.
Female: The scutum is short and wide, with length not quite equalling width. Although Neumann originally described it as longer than wide, this is not true of the only available paratype specimen (cf. Hoogstraal 1953D). The posterior margin is broadly rounded. Lateral grooves are absent or slightly indicated posteriorly; cervical grooves are deep basally, distally superficial, and extend almost to the eyes or slightly beyond the eyes. Scutal punctations are variable in number but few, fine, and distant with very few, almost obsolete interstitials. The eyes are flat and on or very slightly removed from the lateral margin.