April, '09] ENTOMOLOGICAL NEWS 159 



Two Fossil Bees. 



By T. D. A. COCKERELL. 



The numerous bees from Baltic amber which I have recently 

 had occasion to study, all belong- to extinct genera. In this 

 they differ from some of the other amber Hymenoptera, 

 which belong to genera still living, e. g., Pison, Crabro and Ha- 

 dronotus. The bees are believed to have arisen from the fos- 

 sorial wasps, and no doubt many wasp-genera are of great an- 

 tiquity. The amber insects are of Oligocene age and are pos- 

 sibly as much older than those of Florissant, as the latter are 

 than those now living. The Florissant bees include both liv- 

 ing and extinct genera; the latter not ancestral, apparently, to 

 any now existing. During Miocene times, this country had a 

 warmer climate than at present, and doubtless supported a larg- 

 er insect fauna. Later, especially at the time of glaciation, 

 the fauna must have been greatly reduced, and it appears that 

 many genera became extinct ; some entirely so, others (as 

 the tsetse fly) surviving on other continents. Even the warm 

 period was probably fatal to many old American genera, be- 

 cause it permitted the immigration of numerous old-world 

 forms via Alaska, and thus set up injurious competition. The 

 details of the great Tertiary biological drama are gradually be- 

 ing made out through a study of the fossils, and it is becoming 

 increasingly evident that these must be considered in connec- 

 tion with the living genera, in order to understand the one or 

 the other series. Most students of recent insects have hereto- 

 fore ignored the results of the palaeoentomology, but it is hoped 

 that in the future they will gladly utilize the significant facts 

 available from this source. 



PELANDRENA K en. nov. 



Allied to .-Indrcna, but with only two submarginal cells in 

 the anterior wings; second submarginal broad, much con- 

 tracted apically, receiving the first recurrent nervure some 

 distance from its base, and the second at its apex ; lower sec- 

 tion of basal nervure very much longer than upper, practically 

 straight, except at the lower (basal) end, where it is bent 



