"'I 



ANTS. 



the Tertiarv lakr> o f ( k'liiiigcn, Radoboj and Florissant must have been 

 iniu-li smaller, shallower and calmer bodies of water, and the insects 

 that dropped into them or were swept into them by streams, were 

 probably imbedded in the mud under water. Many of them were, of 

 course, devoured by tishes. Professor Cockerell has sent me from 

 Florissant >r\nal specimens of fossil fish excrement consisting almost 

 entirely of the hard indigestible heads of ants. It is very unfortunate 

 for the student that so few of the workers of the Oeningen, Radoboj 

 and Floris>ant ants have been preserved, for our knowledge, as 

 we have seen, is largely based on the worker caste and the males and 

 females even of recent forms are so imperfectly known that fossils of 

 these sexes are very difficult to classify, especially when the characters 

 of most taxonomic value, such as the shape of the head, mouth-parts 

 and abdominal pedicel are obliterated by flattening and distortion. 

 Another great difficulty is encountered in attempting to correlate the 



FIG. 94. Worker of Elec- 

 tromynne.v klebsi sp. nov. from 

 the Baltic Amber. (Original.) 



FIG. 95. Worker 

 of Stigmomyrmex 



venustits from the 

 Baltic Am be r . 

 (Mayr.) 



males, females and workers of the same species. This is no easy 

 task with carelessly collected recent ants, but with fossils, except those 

 of the amber, it becomes almost impossible. 



The ants of Oeningen and Radoboj were first studied by Heer 

 (1849, ^5^' ^67) before the taxonomy of recent ants had been 

 placed on a firm basis by the researches of Mayr. It is therefore im- 

 possible to assign most of Heer's species to their proper genera, and 

 although Mayr (1867^) was able to examine a number of the Swiss 

 paleontologist's species, he did not have access to the types. Hence 

 the whole ant-fa-una of Oeningen and Radoboj must be reinvestigated 

 by some one thoroughly acquainted with the recent ants. The species 



