24 B. C. ENTOMOLOGICAL SOCIETY 



philids, and Bil^ionids, have a relatively strong representation, and out- 

 number all other Diptera threefold. Today, these conditions are exactly 

 reversed. The Bibionids were especially prominent, and appear to have 

 formed the principal element of the fauna of that time. They are 

 exclusively represented by the genus Penthetria (Plecia), which through- 

 out the world, at present, includes but few more species than are com- 

 prised in the small collection of Lambe. The number of species of this 

 genus was much larger in the early Tertiary than in the late Tertiary, 

 where the genus Bibio was beginning to become more prevalent, as 

 judged by their geological distribution in the European Tertiary. 

 Hence Handlirsch came to the conclusion that the occurrence of so dis- 

 proportionately large a number of species of Penthetria in the Tertiary 

 of British Columbia, contemporaneous with the absence of Bibio, also 

 indicate that the beds in question belong to the early Tertiary, and are 

 at least Oligocene in age. The genus Bibio is now represented in the 

 American Tertiary and the supposition is that the genus Bibio originated 

 in the East, probably in Europe, and later found its way to America. 

 Today, the genus Penthetria exists principally in tropical and sub- 

 tropical countries. In temperate zones, it survives only in individual 

 forms; one of these being the single dwarf European species P. holo- 

 sericea. Bibio, on the other hand, is especially abundant in the temperate 

 regions of North America and Europe, but is sparingly represented in 

 the South. So much the more interesting, then, is the occurrence of 

 such a large series of fossil species of Penthetria — the representatives of 

 existing thermophilous forms — in a latitude so high as is the region of 

 the Similkameen River. Not only in the Penthetrias, however, but also 

 in Promastax (primitive Acridioid) and the numerous Cercopids, and 

 particularh' in the huge Aphrophora angusta Hand, the fulgorid, 

 Ricania antiquata Scud, etc., are found proofs of a warm climate at that 

 time. These data, therefore, taken together, lead to the safe conclusion 

 that the Similkameen deposits are at least Oligocene in age. 



GEOLOGICAL RECORD 



Although insects have a very long pedigree, it is as yet a very 

 imperfect one. The remains of creatures that can be referred to the 

 class Insecta have been found, it is said, in Silurian strata ; only one 

 or two of these very early forms are at present known, and the informa- 

 tion about them is by no means satisfactory. If insects at all — as to 

 which some doubt exists — they apparently belong to very different 

 forms, though, like all the earliest fossil insects, they are winged. In 

 the strata of the Carboniferous epoch numerous insects have been 

 detected, in both Europe and North America. These early insects are 

 called by Scudder — quoted by Sharp (8, p. 486) — Palaeodictyoptera. 

 According to this author they are separated from the insects around us, 

 because he considers there existed among the Palaeozoic insects no 

 ordinal distinctions such as obtains in the existing forms, but that the 



