Unstudied.

DISEASE RELATIONS

REMARKS

The frequent records of specimens taken from grass are due to the large size and conspicuousness of the rhinoceros amblyomma.

This species often has been referred to as A. petersi (Karsch, 1878), but according to Schulze (1932A), this name is synonymous with A. rhinocerotis (de Geer, 1778). This decision is acceptable for the present, but it must be noted that Theiler (correspondence) is far from certain of its validity. Obviously needed is a careful study of the original material and literature by a competent contem porary student with full access to pertinent specimens.

The specific name rhinocerotis (de Geer, 1778) frequently has been applied to Dermacentor rhinocerinus (Denny, 1843). However, as Bequaert (1930B) pointed out, Donitz (1910B) has long ago indi cated that de Geer's specimens belonged in the genus Amblyomma because of their longer palpi.

The remarkable parallel or convergent evolution of rhinocerosinfesting Amblyomma and Dermacentor ticks, and the relationship of Cosmiomma hippopotamense (Denny, 1843), a hyalommalike beast, is worthy of special study.

The capsule of larval haller's organ in A. rhinocerotis has been noted by Schulze (1941), who also (1950A) discussed the adult dentition of this species.

IDENTIFICATION

Males, at least 8.0 mm. long and 7.0 mm. wide, are as large as any other African amblyomma. The scutum lacks lateral grooves, has bicolored festoons, small and flat eyes, extensive pale (yellowish) ornamentation on a dark (reddish brown) background, and a few large scattered punctations. The leg segments have narrow pale distal rings.

Females are also very large, approximately 9.0 mm. long and 8.0 mm. wide. The scutum is largely pale (reddish or golden) with lat eral margins and small internal areas dark reddish-brown; it bears few coarse punctations on the anterior half but numerous fine punc tations; eyes are flat or very slightly convex. The leg segments exhibit narrow, pale distal rings.

King (1926) listed Equatoria Province without localities and his specimen vials include no further data. The nymph from a chameleon was identified by Dr. G. Theiler.

DISTRIBUTION IN THE SUDAN

Although it may have been reasonable to expect that A. tholloni occurs on elephants in Bahr El Ghazal and Upper Nile Province and on the west bank of Equatoria Province, no specimens have been col lected to indicate its presence in these places. Ticks from several elephants shot near Yirol and Kenisa in Bahr El Ghazal and Upper Nile Provinces in 1911, 1953, and 1954, have all been R. simus simus, R. simus senegalensis, or intergrades of these two subspecies.

DISTRIBUTION

A. tholloni occurs through much of tropical Africa, wherever the African elephant, Loxodonta africana subspp., is found, except possibly along the northern and southern margins of the host's range.

WEST AFRICA: LIBERIA (Bequaert 1930A). SIERRA LEONE (Simpson 1913. Robinson 1926). IVORY COAST (Rousselot 1951,1953B. Villiers 1955).

CENTRAL AFRICA: CAMEROONS (Neumann 1901,1911. Ziemann 1905, 1912A. Rageau 1951,1953A,B). RIO MUNI (Robinson 1926). FRENCH EQUATORIAL AFRICA (Neumann 1899. Tonelli-Rondelli 1930A. Fiasson 1943B. Rousselot 1951,1953B. Rageau 1953B).

BELGIAN CONGO (Neumann 1899,1911. Nuttall and Warburton 1916. Roubaud and Van Saceghem 1916. Robinson 1926. Schwetz 1927A,B,C, 1932. Schouteden 1929. Tonelli Rondelli 1930A. Bequaert 1930A,B, 1931. Rodhain 1936. Fain 1949. Theiler and Robinson 1954. Van Vaerenbergh 1954).

NOTE: According to Theiler (correspondence), the record for Ruanda Urundi by Santos Dias (1954D) is in error.

EAST AFRICA: SUDAN (King 1911,1926. Robinson 1926. Hoogstraal 1954B).

KENYA (Neumann 1922. Lewis 19310,1932. Mulligan 1938). UGANDA (Neave 1912. Robinson 1926. Tonelli Rondelli 1930A. Mettam 1932. Wilson 1950. See HOSTS below). TANGANYIKA (Neumann 1899,1907, 1910B,1911. Morstatt 1913. Robinson 1926. Hoogstraal 1954C. J. B. Walker, unpublished; see HOSTS below).

SOUTHERN AFRICA: ANGOLA (Gamble 1914. Robinson 1926. Santos Dias 1950). MOZAMBIQUE (Santos Dias 1947A,B,1948,194,D,1950B, 1953B,1955A. Bacelar 1950. Tendeiro 1952F). Tendeiro 1952). NYASALAND (Neumann Robinson 1926. Wilson 1950B).

1899*. Neave 1912.

Neave 1912. Robinson 1926.

A. tholloni has not yet been recorded from the UNION OF SOUTH AFRICA, but Theiler (correspondence) believes that this is probably because it has not been looked for and that it possibly occurs on Kruger Park elephants and on remote herds in Southwest Africa. possibility that this tick is incapable of following its normal

The

*The reference to "region du Nyassa" by Neumann (1899), for specimens collected by Ed. Foa, may refer to Niassa Province, Mozambique.