267 



" Surface apparently smooth. Cephalon and thoracic segments un- 

 known. 



"Lower rapid, one imperfect pygidium ; middle rapid, the largest and 

 most perfect pygidium collected (fig. 1) ; and foot of portage road, one 

 imperfect pygidium and two fragments." 



Beonteus aquilonaeis, Whiteaves. 

 Plate 42, fig. 2. 



Bronteus aquilonaris, 'White&ves 1904. Geol. Surv. Canada, Aijn. Rep., vol. 



XIV, pt. F, p. 58. 



" Pygidium of medium size, apparently not exceeding an inch and a half 

 in width, transversely subelliptical and much wider than long, with an 

 almost flat but slightly convex axis, and still flatter pleural region. Axis 

 short, inversely subtriangular, with an obtuse apex and somewhat concave 

 sides, nearly twice as wide as long, almost smooth but marked with one 

 transverse furrow near tho anterior margin ; median rib a little wider 

 than any of the lateral ribs and bifurcate posteriorly ; lateral ribs seven 

 on each side, straight and flattened convex, all of the ribs fading out 

 before reaching the margin. 



" Surface apparently smooth. Cephalon and thoracic segments un- 

 known. 



"Portage road at falls, thre3 pygidia, each with the axis imperfect ; and 

 foot of portage road, one pygidium with the axis well preserved (fig. 2). 



"Bronteus Niagarensis, Hall, from the Niagara limestone of Ontario, 

 has a much larger pygidium, with the midrib entire and contracted at its 

 midlength, while the lateral ribs are wider and flexuous. B. acamas, 

 Hall, from 'limestone of the Niagara group at Wisconsin' and Ontario 

 (which S. A. Miller says is a synonym of B. occasus of Winchell and 

 Marcy) has a much larger and more pointed pygidium, with an ' entirely 

 simple ' and undivided midrib. B. insularis of Billings, from the Anti- 

 costi group of Anticosti, is a diminutive species with a pygidium less 

 than half an inch wide and wider than large ; while B. Pompilius, Billings, 

 from the Silurian (Upper Silurian) rocks at Port Daniel, has a small pygidi- 

 um with a ' longitudinal median lobe in the axis.' " 



Ceeaurus TarqUinius, Billings (Sp.). 



Ckeirurus Tarquinius, Billings 1863. Proc. Portland Nat. Hist. Soc, vol. 



I, p. 121, 6g. 22. 



Portage road at falls, and foot of portage road. At each of these 

 localities two heads were collected, which seem to be essentially similar to 

 the types of C. Tarquinius, from Port Daniel, in the Museum of the Sur- 



