ii8 The Ottawa Naturalist. [September 



exposed in a transverse fracture, is eccentric and so large that 

 it may be moniliform. 



Trenton limestone, Mile End, Montreal, T. C. Weston, 1866; 

 one specimen about four inches and a half in length. 



The writer has much pleasure in associating this singular 

 species, which seems to be well characterized by its distant and 

 very oblique flattened annulations, with the name of its discoverer. 



Orthoceras BEAUPORTENSE. (Sp. nov.) 



Shell rather below the medium size, longicone, straight and 

 tapering so gradually that the few specimens which the writer 

 has seen are almost cylindrical. Surface marked by low, roun- 

 ded, narrow transverse annulations, with numerous minute and 

 close set, transverse thread-like raised lines between and upon 

 them, all of which are crossed by small and narrow but com- 

 paratively distant longitudinal ribs or ridges. The transverse 

 annulations average from two and a half to three millimetres 

 apart, at their summits, and are separated by shallow depressions 

 nearly twice as wide as themselves. The longitudinal ribs or 

 ridges are equidistant, uniform in size, and, on an average, 

 about one millimetre and a half apart. The crossing of these 

 ribs by the transverse annulations makes a very regular and 

 rectangular reticulation, which is plainly visible to the naked 

 eye, but the crowded transverse raised lines cannot be well seen 

 without the aid of a lens. Internal structure and shape and 

 relative position of the siphuncle unknown. 



Trenton limestone at Parent's quarry, Beauport, near 

 Quebec City, D. N. St. Cyr, 1888 : one well preserved testiferous 

 specimen not quite two inches in length and with a considerable 

 portion of its surface buried in the matrix. A similar specimen, 

 but with the whole of the outer surface visible, from the same 

 locality, has been lent to the writer by the authorities of Laval 

 University. 



This finely sculptured shell seems to be closely allied to the 

 O. pseudocalamiteum (Quenstedt) Barrande,* but to want the 



*Systenie Silurien de la Boheme, Vol. II, Texte 3, 1874, p. 261, pi. 217, fig. 8 ; 

 pi. 222, figs. II, 12 ; pi. 228 ; pi. 236, figs. 11-16 ; and pi. 361, figs, 15-17. 



