110 The Ottawa Naturalist. [Dec. 



The ripple-marked beds of the Snake Island section lie 

 not far above the Stringocephalus dolomite. Since the dolomite 

 bearing Stringocephalus burtoni does riot appear in the Snake 

 Island section, the precise distance of the ripple-marks above 

 this formation cannot be stated. They belong near the base of 

 a formation called the Manitoban. The following fossils, deter- 

 mined by Prof. J. F. Whit eaves, are recorded from the lime- 

 stones of this formation on Snake Island by Tyrrell : 6 



Cyathophyllum vermicular e var. precursor, 



Alveolites vallorum, 



Atrypa reticularis , 



A. as per a, 



Cyrtina hamiltonensis , 



Rhipidomella striatula, 



Paracyclas elliptica, 



Raphistoma tyrrelli, 



Belerophon pelops, 



Euomphalus subtrigonalis , 



Omphalocirrus manitobensis , 



Cyrtoceras occidentale, 



Gyroceras submamillatum, 



Dinichthys canadensis. 

 To this list may be added Astraeospongia hamiltonensis. 

 The small six-rayed spicules of this sponge occur in large 

 numbers in a band of limestone 8 inches below the top of the 

 cliff shown in figure 2. On the evidence of this fauna these beds 

 were assigned to an Upper Devonian horizon by Whit eaves. 7 



POPULAR ENTOMOLOGY. 



The Engraver Beetles (Family Ipid^e). 

 (Continued from Vol. XXV, page 145.) 



By J. M. Swaine, Assistant Entomologist for Forest Insects, 

 Division of Entomology, Ottawa. 



The Ambrosia-beetles, or Timber-beetles, breed entirely 

 within the wood, the eggs of some species being laid well within 

 the heart-wood. They bore small, round tunnels directly 

 through the bark and into the wood. There may be several 

 secondary egg-tunnels cut by two or more females, branching 

 from a primary entrance-tunnel. On the other hand the tunnels 



Geol. Surv. of Can., Pt. E. Vol. V, 1889-90-91 (1892), p. 163 E. 

 7 Contrib. Can. Pal., Vol. I, Pt. IV, p. 258, 1892. 



