126 FORMICID.E. 



this genus the apex of the pedicel is fixed to the upper margin of 

 the base of the abdomen, as noted above, and the upper surface of 

 the abdomen itself is more or less flat, the lower surface convex. 



Or emastog aster bites virulently, but I do not think uses its sting 

 much. Like very many other ants it tends and keeps "ant- 

 cattle." According to Messrs. Aitken and Taylor, some species 

 build special byres for their " cows." C. difformis, physothorax 

 and inflatus have the metachorax remarkably large and swollen, 

 with a hollow on each side iateriorly, communicating exteriorly by 

 a tiny aperture. In live specimens there seems to be a continual 

 flow from this aperture of a sweet fluid, and I have watched the 

 workers of C. physothorax licking one another's thoraces vigorously. 

 No species, so far as I know, stores food ; but Mr. Wroughton has 

 recorded having witnessed Cremastoy aster perelegans robbing Holco- 

 myrmecc of grain, which the latter was harvesting. 



Many instances have been noted of woodpeckers, and these, so 

 far as I know, belonging exclusively to the genus Hicropternus, 

 digging their nest-holes in nests of Cremastogaster. Three such 

 nests which I myself found in Burma belonged to M. phceoceps, 

 Blyth. Of these, two had been excavated in the nests of C. ebe- 

 nina, Forel, and the third in the nest of C. artife,v, Mavr. In 

 none of the nests were there any ants left. They had either 

 deserted or been eaten up. That the ants, however, sometimes 

 continue to inhabit their nest after it has been taken possession of 

 by the woodpecker is recorded by Wroughton in a note sent to him 

 by Mr. Aitken. 



Key to the Species *. 



A. Metathorax not swollen ; metanotum 



bispinous. 

 . Head smooth and shining, at most with 



a few half-obsolete striae anteriorly. 

 a'. Club of nagellum of antennae 4- 



jointed C. wroughtoni, p. 128. 



b'. Club of flagellum of antennae 3- 



jointed. 

 2 . Pronotum sculptured. 



a 3 . Pronotum convex, rounded in 



front. 

 *. Lateral angles of pronotuui 



prominent C. contemta, p. 130. 



6 1 . Lateral angles of pronotuni 



not prominent C. buddluc, p. 132. 



b 3 . Pronotum flat above, rounded in 



front. 

 a 4 . Eyes elongate C. hodysoni, p. 131. 



* C.ferrarii, Eruery, which is unknown to me, and of which the description 

 is very brief, has been omitted in this key. A translation of the description is, 

 however, given further on (p. 144). 



