The Ants of the Baltic Amber. 
45 
Tribe Monomoriini, trib. nov. 
Genus Monomorium Mayr. 
Monomorium pUipes Mayr. (Fi g. 14.) 
Monomorium pilipes Mayr, Beitr. Naturk. Preuss. I, 1868, p. 91, Taf. V, Figs. 93, 94, 5; 
Dalla Torre, Catalog. Hymen. VII, 1893, p. 69; Ern. Andre, Bull. Soc. 
Zool. France, XX, 1895, p. 82; Handlirsch, Foss. Insekt. 1908, p. 872. 
Twenty two workers of this species, all in the Geolog. Inst. 
Koenigsberg Coli., have been examined, namely: No. 137/3789 (seen by 
Mayr and doubtfully referred to this species), XXB 2168, XXB 813, 
XXB 1550, XX 1897, XIII B 3000, B 5338, B 19461, B 304, B 19401, 
B 251, B 5367, B 18477 and nine without numbers. 
The mandibles have 5 subequal teeth; the mesoepinotal constric- 
tion is pronounced, the epinotum subangular in profile, with subequal 
base and declivity, the former feebly 
convex, the latter sloping and slightly 
concave. Antennse 12-jointed. The pe- 
tiole has a well-developed, rounded and 
anteroposteriorly compressed node and 
a distinct pednncle. The postpetiole is 
lower and more tounded than the 
petiolar node. The mesopleurse and 
epinotum are longitudinally rugulose, 
the remainder of the body smooth and 
shining, with scattered piligerous punc- 
tures, which are most distinct on the 
head and gaster. Most of the specimens 
are brown or reddish throughout, a 
few, which are more decomposed, are black. Length 2 — 2,5 mm. 
Mayr states tliat this species is most closely related to the living 
M. destructor Jerdon (= M. basale F. Smith), an originally paleotro- 
pical ant now common also in neotropical countries. M. destructor , 
however, has a, much more slender thorax, petiole, postpetiole, antennse 
and legs than M. pilipes. 
Fig. 14. 
Mohomorium pUipes Mayr. 
Worker. 
Monomorium mayrianum 9 nom. nov. (Fig. 15.) 
Lampromyrmex gracillimus Mayr, Beitr. Naturk. Preuss. I, 1868, p. 95. Taf. V, 
Figs. 97, 98, Dalla Torre, Catalog. Hymen. VII, 1893, p. 78; 
Handlirsch, Foss. Insekt. 1908, p. 873. 
This form unquestionably belongs to the genus Monomorium as 
at present defined. Mayr was apparently induced by the 11-jointed 
