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tuberance is found on the inner margin ventrally of the basal pal. pal segment. The inner margin of the basal segment is short and deeply concave by comparison with that of B. annulatus. The palpi usually appear more compact and 1ess'acut§Iy ridged.
Minning's (1934) character for separating B. micro us and B. fallax on the basis of the anterior curvature of_p§lg%I-segment 3 applies only to his illustrations, not to specimens. The scutum, normally slightly longer than wide, may be widened by engorgement (from 0.40 mm. to 0.58 mm. long and from 0.34 mm. to 0.50 mm. wide). The eyes are generally oval and raised above the scutal surface but this character may be difficult to discern. Size varies from about 2.0 m. to 12.5 m. long, and from 1.0 mm. to 7.9 mm. wide, depending on degree of engorgement.
Dermacentor, a medically important genus in nany parts of the world, is represented by only three species in tropical Africa. Snnll populations of two of these, D. c. circ ttatus and D.
rhinocerinus, occur in Equatoria and B-a'hr az ovince§ of HE SEan. In Africa they are always rather rare and largely con.
fined to the rhinoceros and elephant. As such, they are of little more than academic interest. The identity of these species my be determined easily from the following keys and illustrations.
The third African species, D. hi tamensis (Denny, 1843) (= Ixodes bimculatum Denny, 181.3, ~i yomma 1‘ tami Koch, 1841.), was origJ.T-any described from Hipggtamus a.mp%bius of South Africa. Schulze (1919) erected the genus Cosmiomma for this species on the basis of its H lomma.like characters although it lacks accessory shields and su shields. Zumpt (1951) sank Cosmiomma under Dermacentor but Theiler states (correspondence) tfit Schulze's definition justifies its retention as a genus. Other authors have placed it in H alomma. Still another study by a qualified student on the originil mterial appears necessary be. fore an acceptable systematic niche can be found for Q. (0.) gigg
Q. (0.) hi tamensis has been re rted from South Africa and between "ZanzI%' (i .e. East Africa)°and the Great Lakes (Tan. ganyika). For over a century, the only positively known specimens have been the types described by Denny and by Koch, which have been seen again by later students. In the collections of the East Afri. can Veterinary Organization there is a single male taken from vege. tation at Manyani, Teita District, Kenya, 5 November 1951, D. L. U. Sheldrick legit. This specimen, according to J . B. Walker (cor. respondence), is almost exactly like the type material illustrated by D'8nitz (l9lOB). One or two specimens are in the collection of the Veterinary Department at Kabete, Kenya.
2. (§.) hi tamensis is a large, brightly colored Ambl me. like tick. The %e scutum is described as pale straw.yelIow with symmetrical black nnrlcings and a few smll punctations; ventrally
the legs are a deep liver..red. The female scutum is lightly punctate, largely pale in color with two subnndian longituiinal black stripes and a pair of vertical black stripes near the posterior mrgin. The dorsal surface of the female posterior of the scutum is dull crimson with two large nearly circular, slightly elevated orange spots near the lateral margin. The apex and lateral m.r.. gin of the pelpi are dull crimon. The last tarsal segment and ventral surfaces of the legs are colored as in the nnle. This all but extinct beast should not be difficult to recognize.
Another species, 2. niveus Neumnn, 1897, parasitizes wild boars in Tunisia, Algeria, § Spanish Morocco (Senevet, ColesBelcour, and Gil Collado 1933), and various other animals in Europe and Asia.
It is difficult to determine what ‘'2. reticulatus Neunnnn,“ listed by Stella (l938A,l939A,l940) from E1-.TE_"_?n‘d'op1a by Niro (1935) from Sonnliland, actually is. Q. reticulatus, which does not appear to be a synonym of Q. nar inatus 335., I776, as stated by Schulze (19330), inhabits Europe As a. If its range does extend into the Ethiopian nmmtains, it would represent a unique ixodid distributional pattern, but conceivable on the basis of geographic distribution of other invertebrates.
Although it has not been our policy to discuss non..Sudanese species, the above remarks and a few additional taxonomic notes are inserted inasmuch as no review of the genus Dermcentor in Africa is available. Extra.-Sudan species have not been demons_ trated to be of medical importance and will not be included in subsequent volumes of this undertaking.
In various papers on Dermacentor, Schulze has divided the genus into several genera that show in' terrelationships within a closely circumscribed group and can, by contemporary concepts, be considered at most only as subgenera. These are of only slight interest in Africa, especially as the moot subject of subgenera will be further revised in future studies. D. circ tatfis was placed in the subgenus Ptmcticentor, which was sufiequently sync. nymized (Zumpt 1951) under the subgenus Amb centor, in which D. rhinocerinus had been placed. The usefulness of the latter <=a1-.‘é.
gory J.S questionable in the absence of study of the entire genus.
These same remarks are possibly pertinent to the subgenus Cosuriomun, originally proposed as a full genus embracing only 2. 'pEEtamensis.
Ornamentation consisting of eight snnll ,
—Fi'g'u.res 125 E El
Ornamentation consisting of seven large
pale spots, which cover most of scutum, and of smaller peripheral and festoon
Scutum largely dark, ornamented with
th]-'88 P618 Smtsoooo0000ooooooooooonoooooooooo-P-0 20 Figures I21 FE D5
Scutum largely pale , a few small dark