W. L. Brown, Jr.
A New Discothyrea from New Caledonia (Hymenoptera: Formicidae).
Psyche 55(1):38-40, 1948.

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A NEW DISCOTHYREA FROM NEW CALEDONIA
(HYMENOPTERA : FORMICID&)
BY WILLIAM L. BROWN, JR.
Biological Laboratories, Harvard University. I have recently received a small collection of ants made by Charles L. Remington on New Caledonia during the spring of 1945.
Among them is a single specimen of
a new species of the interesting genus Discothyrea Roger. This genus, hitherto unrepresented on the island, belongs to a group of relict genera occurring in New Zealand, Australia, the East Indies and the warmer parts of the Americas. The find would seem to further strengthen the belief in the Australia-New Caledonia-New Zealand land-connections hypothesized as existing in the past, and would also further indicate a past contact between these areas and South America.
Discothyrea remingtoni new species
Worker. Total length measured from anterior cly- peal border of the extended head to the posteriormost point on the curved surface of gastric segment 11, 2.6 mm.
Length of head alone, 0.80 mm.; Weber's length of thorax 0.73 mm. ; length of petiole, 0.19 mm. ; of raster, measured around the curve of the vault to the anteriorly directed last segmental apex, 1.24 mm.
Head from the front broadly oval, cephalic index 88; broadest at about the posterior third of its length, with the sides somewhat converging and only slightly convex anteriorly; the posterior corners broadly rounded and passing easily into the evenly convex posterior border. Seen from the side, the posterior corners are evenly rounded. The structure of the frontal region and car- inal plate much as in other Discothyrea species, the median ridge continuing upward to beyond the mid- length of the head. Clypeus moderately projecting, broadly rounded anteriorly. A slight area above each antenna1 insertion on each side of the carinal plate very weakly impressed. Mandibles short, strong, convex, 38
Pu&e 55:38-40 (1948). hup ttpsychu einclub org/S5/55-038 html



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1948 J Brown~A New Discothyrea 39
with knife-edged inner (masticatory) borders and acute apices. Antenna1 scapes massively clavate, their respec- tive funiculi eight-jointed, the last joint exceptionally large and heavy.
Eyes a little larger than most Dis-
cothyrea, with more than 12 and less than 18 ommatidia in each, situated just above the anterior quarter of the sides and a little toward the front or dorsal side of the head.
Fig. 1. Discothyrea remingtoni new species, worker. A, petiole and adjoining segments in profile; B, antenna. Thorax not radically different from the usual run of Discothyea, rather stout, with blunt, rounded humeral angles ; epinotal teeth low and blunt, their bases ex- tended down the sides of the epinotal declivity as low vertical lamellae. The teeth are located somewhat far- ther down the epinotal declivity than in Emery's figures of clavicornis in the Genera Insectoruni and in the ori- ginal description of that species (1).
The petiole is in the form of a thickened disc divided, in at least the dorsal half, by a transverse sulcus into an- terior and posterior low, rounded rims, the central planes of which are parallel to each other, the anterior being slightly the larger of the two. Seen from the rear, the profile gives the effect of a semicircle within a concentric semicircle, the anterior rim being the outer semicircle and the posterior the inner. The posterior rim is truncate at its highestpoint, thus providing a collar for the reception of the base of the first gastric segment. The sulcus which runs around the dorsum ends halfway down the sides of



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40 Psyche
[Mar.
the node described ; the median ventral keel is moderately prominent and bears a blunt process anteriorly. The gaster long, its second segment vaulted in the manner of most proceratiine ants and the undercurved apical seg- ments directed anteriorly.
The integument in general clearly shining through the dense pilosity, very sparsely and finely punctulate. The impressed spaces on each side of the median facial ridge coarsely and closely punctate, scarcely shining. Clypeus,
carinal fusion process and antennae finely reticulate- punctate, subopaque to opaque.
The entire body clothed densely with short suberect to erect whitish hairs, which are slightly shorter on the head and antennae, slightly more sparse on the legs. Head ferrugineous yellow, the gaster, mandibles and antennae somewhat lighter ; thorax rich mahogany red, - -
the petiole lighter; legs and tip of gaster medium yellow. Holotype: One worker deposited in the Museum of Com- parative Zoology, No. 27788. Labelled "7 mi. S.E. La Foa, New Caledonia, Rocky Humus. March 11,1945 (C. L. Remington)."
The nearest species of the genus in size is D. antarctica Emery (Z), which measures 2 mm., but antarctica is yel- low throughout and has a differently shaped petiole. D. globus Forel and D. clavicornis Emery are much smaller and are described as having opaque integument; globus is red-brown throughout and clavicornis "flava"; both have differently shaped petioles. Mann (3) described specimens of clavicornis from the Solomons as "rich brownish red." Since Emery's type is a unique and possibly teneral, it would be best to wait for further col- lecting before formally differentiating Mann 's specimens as a color race. Forel's var. sauteri of globus from Formosa should be accorded at least subspecific rank on the basis of the description (4).
Ì LITERATURE CITED
(1) Emery, C.
Termes. Fuzetek (1897) 20: 593, PI. 15, figs. 39, 40. (2) . Zool. Jahrb. Syst. (1895) 8: 266.
(3) Mann, W. M.
Bull. Mus. Comp. Zool. Harvard (1.919) 63: 288. (4) Forel, A. Ent. Mitt. (1912) 1: 47.




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