William L. Brown, Jr.
A New Ant of the Genus Epitritus from South of the Sahara.
Psyche 69(2):77-80, 1962.

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A NEW ANT OF THE GENUS EPITRITUS
FROM SOUTH OF THE SAHARA*
BY WILLIAM L. BROWN, JR.
Department of Entomology, Cornell University Recently Mr. G. E. J. Nixon, of the Commonwealth Institute of Entomology in London, sent me a small series of a curious ant that he had recognized as an aberrant and possibly undescribed species of tribe Dacetini. Upon receiving the specimens, I found that the sample represented a new Epitritus, the first member of the genus from Ethio- pian Africa, and the first to be found in the tropics. I am grateful to Mr. Nixon for making available this most interesting new species. Epitritus laticeps sp. nov.
Figures 1-4
Holotype worker: TL 2.2, HL 0.47, HW 0.58 (CI 123), ML 0.22 (MI 47); WL 0.49, scape L 0.29, funiculus L 0.43 mm, of which about half is taken up by the apical segment. Measurements and proportions are those standard in my other dacetine studies (see Brown, 1953, Amer. Midi. Nat. 50: cf. pp. 7-15). Shape of head, body and mandibles as shown in Figs. 1-4. Especially characteristic of the known species of Epitritus and (judging from two occipital lobes (which make the head distinctly broader than long) ; the wide, basally lobiform antenna1 scapes; the large, conical labral lobes; the 4 long straplike clypeal hairs and the peculiar mandibles, lacking a long, spiniform dorsal "apicalw tooth and with only a single preapical tooth. The apex of the mandible is of the "inverted" type characteristic of the known species of Epitritus and (judging from two paratype workers of which the mandibles were opened) has 7 or 8 denticles, of which one or two in the middle are round-edged, and the rest are acute. The basal lamella is small, with acutely rounded apex (Fig. 3), and the ventro-medial margin below it is obtusely denticulate or angulate (not shown in figures). Eyes minute, with only 4-6 facets. Antenna1 funiculus clearly 5-segmented.
Promesonotum seen from above broadly oval, almost circular, nar- rowest behind, where it is terminated by the fine but distinct metanotal groove, which crosses just behind the highest point of the swollen mesonotum. Propodeurn much narrower than pronoturn, with high, *Manuscript received by the editor December 15,1961.



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78 Psyche [June
angular lamellae guarding the concave declivity, the declivity reaching far up towards the metanotal groove.
Petiolar node distinct from its anterior peduncle, as seen from above transverse, subrectangular, about twice as broad as long. Postpetiole Figures 1-4. Epitritus laticeps sp. nov., paratype worker. Fig. 1, side view
of head and body. Fig. 2, dorsal full-face view of head and mandibles. Fig.
3, oblique dorsal view of opened left mandible. Fig. 4, ventral inside oblique view of apical group of teeth or denticles. Drawn by F. A. McKittrick. much broader than petiole and more than twice as broad as long, convex above with a shallow median impression, articulated to the entire width of the anterior gastric margin. Spongiform appendages limited to narrow posterodorsal lamelliform collars on both nodes, and absent from antesoventral face of gastei-. Gaster laterally sub- marginate at the extreme base; short, coarse costulae fade caudad into superficial, indistinct reticulation reaching nearly to the midlength of the basal segment; gaster otherwise shining and smooth. Body reticulate-punctulatc, opaque, except for the gaster, the inner mandibular surfaces and the labral lobes, which are smooth and shin- ing. Specialized pilosity, especially the large orbicular, cochlear hairs



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19621 Brown - Epitritus 79
of the head, and the spatulate ones of the scapes and cly~eus, as shown in the figures. Slender, erect spatulate-to-clavate hairs in rows of 4 or 6 on gastric dorsum, totalling about 32. Ground ~ilosity reduced to minute stubby hairs, chiefly on promesonotum and nodes, and sparse, short idinate hairs on gastric dorsum and legs. Tibiae and tarsi with longer reclinate hairs, some of them spatulate. Gula with fine reclinate hairs. Co,lor medium ferruginous ; head feebly infuscated dorsally ; appendages more el lo wish.
Holotype [British Museum (Natural History) ] and six paratype workers [deposited with holotype and in Museum, of Comparative Zoology at Harvai-d College] taken in northern Nigeria near Zungeru on the Kaduna Road, 19 December, 1956, from "base of dead tree" by W. A. Sands of the Termite Research Unit (Collection No. S 780). The paratypes are quite similar to the holotype, and range from the same size down to the smallest specimen : TL 2.0, HL 0.46, HW 0.55 (CI 120), ML 0.22 (MI 48), WL 0.49 mm. Cephalic index range for the entire type series is 119-125. There is slight variation in the size and shape of the small teeth or denticles in the apical com- plex. Female and male unknown.
E. laticeps can be separated from its two congeners by means of the following key :
I. Tooth at apparent (dorsal) apex of mandible small, about equd to or slightly longer than the other largest teeth of the apical group; promesonotum without conspicuous hairs of any kind (Nigeria) ............................................................ Zaticeps Brown Tooth at apparent (dorsal) apex of mandible long, straight and spiniform, about 2 or 3 or more times as long as the largest of the other teeth in the apical group; promesonotturn with numer- ous large orbicular scale-like hairs like those of the dorsum of ............................................................................ the head 2.
2. Funiculus with 5 separate segments; mandible with two pre- apical teeth (Japan : Kyushu, Honshu) ........ hexamerus Brown Funiculus with only 3 separate segments; mandible with 4 pre- apical teeth (Mediterranean lands n. to Hungary) ............................................................................. argiolus Emery The finding of a species of Epitritus south of the Sahara marks the genus as a zoogeographical curiosity of more than usual interest. Of the two previously known species, E. argiolus is widespread in southern Europe and North Africa, while E. hexamerus has been taken twice in Japan. Evidently, Epitritus is a relict-distributed group that was once more widely distributed in the tropical and warm temperate



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parts of the Old World. The insects are cryptobiotic in habits, and are small and inconspicuous, so we may look forward to the discovery of species elsewhere in the Old World.
Another interesting thing about the new species is its close conver- gence in many morphological details to Talari!dris mandiblularis Weber (tribe Basicerotini) of Trinidad and British Guiana (see Brown and Kempf, 1960, Stud. Ent., Petropolis, (n,s.)3: 233, 241-242).



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