94 CONTEIBUTIONS TO CANADIAN^ PALAEONTOLOGY 



that no apterous larval form of any kind is present, and not a single 

 species living under the water. The question, itherefore, is probably, 

 'whether the deposits from which the insects come were laid down 

 tolerably far from shore, rather than whether they represent dis- 

 tinctly littoral sediments. 



Including the Tertiary insects previously made known from 

 British Columbia — which for the sake of completeness are inserted 

 in my list — tlie epecies may be systematically divided in the follow- 

 ing manner: — 



Orthoptera : Acridioidea. ? MastacinsB, 1. 



Coleoptera: Carabidse, 1; ElateridsB, 5; Buprestidse, 3; Hydro- 

 philidae,- 1; Nitidulidae, 1; Tenebrianidse, 1; Chrysomelidse, 3; 

 ScarabseidsB, 1. (Coleoptera incertse sedis, 3.) 



Hymenoipiiera: lehneumonidse. — ^Pimplinas, 4; Braeonidse, 2; 

 Formieidse, 3. 



? Odonata : ? Libellulidae, 1. 



BapMdioidea : 1. 



Neii/roptera: Hemerobiidse, 1. 



Dipteral Orttic/rrhapUa nematocera. — Mycetophilidse, 5; Bibion- 

 idse, about 35; Ptychopteridse, 1; Ohironomidse (several); Tipulidse, 

 2. Orthorrhapha brachycera. — Asilidse, 1; Empidse 1; Doliehopodidae, 

 1. Gyclorrhapha. — Borboridae (=Acalyptrate Muscidse), 5; An- 

 thomyinsB, 2. 



Hemiptera: Gerridse, 2; Pentatomidse, 2. 



Homoptera; Fulgoridse, 1 (? 2); Oercopidse, 12; Aphididae, 2 (in- 

 certae sedis, 1). 



Insecta incertce sedis, 7. 



It must necessarily prove difficult to judge of the age of given 

 deposits containing insect material, which comprises scarcely one 

 hundred species : many of which, at best, are inaccurately determined, 

 and are in need of critical revision. However, some definite clues 

 have already been obtained. Thus, it has been rendered conspicuous 

 that hitherto no representatives of the latest and most higihly spe- 

 cialized groups of insects have been found. The aphids, museids 

 sensu strictu, syrphids, rhynchophores, cecidomyids, lepidopters, 

 physopods, termites, forfibulids, tarsids, chalcidids, etc., are either 

 absent or are only very feebly represented: as the lamellicorns, for- 

 micids, etc. All these groups have doubtless persisited since the 



