Experimental attempts to transmit heartwater (Rickettsia ruminantium) of cattle through this species have failed.

REMARKS

A. marmoreum is considered by most workers to parasitize chiefly the rhinoceros and tortoise but Theiler (correspondence) has found so much variation in morphology and host data on specimens sent from various parts of Africa that she prefers to refer to all specimens as "A. marmoreum group until they can receive more intensive study. Most of her specimens come from tortoises, a few from Varanus lizards and cattle. She considers the rhinoceros to be an accidental host, or else the host of a separate, as yet unrecognized, species or subspecies. She has large num bers of nymphs of this group from fowls.

Schulze (1932A) realized the complexity of the marmoreum group and proposed new names for specimens from various parts of Africa. Reasons for these differentiations appear quite invalid.

A definitive species name for Sudan material awaits assign The range of variation in even the rather small series of Sudan specimens at hand casts considerable doubt on the validity of all those "related species" that are based on certain aspects of scutal ornamentation or on coxal spur characters.

The structure of the larval eye and its sense organs in specimens of the A. marmoreum group has been described and illustrated by Gossel (1935).

Nuttall (1914A) reported on a malformed specimen of A. marmoreum, from the Sudan, and Schulze (1941) noted characteristics of the haller's organ of this species.

IDENTIFICATION

Males: Large, at least 6.0 mm. x 5.0 mm.

Scutum with

reddish yellow ornamentation that is variable but essentially as illustrated; pale areas in this species are more separated

from each other by dark stripes than they are in A. nuttalli; festoons bicolored; punctations consisting of few, scattered large and numerous small; lateral grooves deep and long; eyes flat.

Females: Large, from 7.0 mm. to 30.0 mm. long and from 6.0 mm. to 20.0 mm. wide, depending on degree of engorgement. Scutum extensively pale ornamented and with central pale area broadly rounded posteriorly; large punctations scattered over surface including from five to twelve on posterior half; eyes flat.

Although the scutal length of A. marmoreum group typically equals its width or is slightly greater than the width, the Sudan specimen illustrated (Figure 74) is exceptional in that its width is considerably greater than length.

AMBLYOMMA NUTTALLI
Sudan specimens

PLATE XXVII

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These specimens indicate the presence of A. nuttalli on both the east and west banks of the Nile in Equatoria Province.

Sudan Government collections contain specimens only from Ossa River (H. H. King legit, 1913), now a part of Uganda. King (1926) mentioned no Sudan locality records for this species.

DISTRIBUTION IN THE SUDAN

Kordofan: As A. werneri (Schulze 1932A), a single specimen from Talodi. The host is most probably the "Cinixys belliana"" mentioned by Werner (1924).

DISTRIBUTION

A. nuttalli is widely spread throughout the African continent within the Ethiopian Faunal Region.

WEST AFRICA: NIGERIA (Simpson 1912A,B. Robinson 1926). GOLD COAST (Robinson 1926. Stewart 1937). FRENCH WEST AFRICA (Villiers 1955). PORTUGESE GUINEA (Tendeiro 1951C,D,1952A,C,D,1953,1954).

CENTRAL AFRICA: CAMEROONS (Dönitz 1909. Rageau 1951,1953A,B). BELGIAN CONGO (Schwetz 1927. Bequaert 1931. Theiler and Robinson 1954).

EAST AFRICA: SUDAN (King 1926. As A. w. werneri: Schulze 1932A. Hoogstraal 1954B).

ITALIAN SOMALILAND (See REMARKS below).

KENYA (Loveridge 1929. Bequaert 1930A). UGANDA (King 1926, see DISTRIBUTION IN THE SUDAN above. Robinson 1926. Mettam 1932. Wilson 1950). TANGANYIKA (Dönitz 1909. Robinson 1926. Love ridge 1923C as A. marmoreum is actually A. nuttalli, see Bequaert 1930A).

SOUTHERN AFRICA: SOUTHERN RHODESIA (Dönitz 1909. Jack 1942). MOZAMBIQUE (Santos Dias 1949B,1950A,B,1951A,1952D,1953B,1955A,B). UNION OF SOUTH AFRICA (Curson 1928. Alexander 1929,1931. Bedford 1932. Neitz 1948).

HOSTS

Adults

All authors list land tortoises (Kinixys spp. or Geochelone pardalis) as the chief hosts of adult A. nuttalli. A record of the side neck turtle, Pelomedusa s. subrufa (= P. galeata), as a host (Santos Dias 1953B) was based on misidentification of Pelusios s. sinuatus, "a species of lesser importance as a host" (Santos Dias 1955B).