106 William Morton Wheeler 



Differing from the worker major in lacking the oceUi, in having 

 the mesonotum less sharply marked off from the metanotum and 

 in having the gaster less convex above and more tapering posteriorly. 

 The head seems also to be smoother and more shining and the front 

 less distinctly and less extensively striated. 



I have redescribed this species in detail because the single worker 

 seen by Emery was rather poorly preserved and in an unfavorable 

 position. The single known living species on wich Andre based the 

 genus Ditnorp/iomyrmex, V. janeti, occurs in Borneo and Sumatra. 

 According to Andre, its workers are dimorphic, differing in the size 

 of the head and body, the latter measuring 6 mm in the soldier and 

 3,5 mm in the worker. Emery has given reasons for supposing that 

 intermediate forms occur, so that the generic name is not very apt. 

 The measurements of D. theryi given above, include also those for 

 the forms which may be regarded as mediae. The size of Emery's 

 specimen (between 5 and 5,5 mm) and its lack of ocelli shows that 

 it was a minor or minim worker. 



I have examined 36 specimens of D. tJieryi, which are distributed 

 as follows: 25 in the Geolog. Inst. Koenigsberg Coll. (B 18900, B 18882, 

 B 14186, B 19494, B 14128, XXB 2048, B 19056, B 19722, B 18757 

 (two specimens in one block), B 19097, B 18726, B 18992, B .5509, 

 B 18416 and ten without numbers); 8 in the Klebs Coll. (K 6397, 

 K 4252, K 4442, K 779, a 21, a 185 and a 245), one in the Berlin 

 Museum (313) and two in the Haren Coll. (976 and 1733). K 6397, 

 which contains two workers, a major and a minor, side by side in 

 the same block, has enabled me to correlate these two phases. In 

 this specimen the major is in a very advantageous position and is 

 beautifully preserved, but the front of the head of the minor is 

 obscured hj cracks in the amber. 



Dimorphomyrmex mayri, sp. nov. 



Worker (Fig. 51). Length about 6,5 mm. 



Differing from D. theryi in the following particulars: The head 

 is proportionally longer and narrower, with larger and more convex 

 eyes; which are nearly half as long as the sides of the head. Ocelli 

 lacking. Clypeus longer and more convex, its anterior lobe more pro- 

 jecting and rounded, the palpi and especially the mandibles decidedly 

 longer, the latter being also more slender, with much less convex upper 

 surfaces and external borders, and the two basal joints of the antennal 

 funiculi are distinctly longer. Mesonotum larger and more convex, 

 petiolar node proportionally broader and shorter, being more compressed, 



