349 



been collected at the Sucia Islands by Mr. Richardson, Dr. Newberry 

 and Dr. Newcombe. The largest specimen in the Museum of the Survey 

 is eighteen inches across, as already stated, on page 110 of this volume. 



Dr. Kossm it writes that the septa of A. Neicberryanus are " certainly 

 not the septa of a Bestnoceras." and adds that the specimens from Cura- 

 shewa Inlet, in the Queen Charlotte Islands, originally referred to 

 Ammonites Beudanti on page 205 of this volume, and subsequently 

 called Desmoceras (Puzozvi) Dmvsoni on page 286 of the same volume, 

 are typical examples of the genus. But, in the second volume of his 

 " Handbuch der Pahtontologie " all that Zittel says of the sutural line of 

 Pachydiscus is, that it is only a little less finely incised than that of 

 Haploceras or Desmoceras. And, it would be difficult to find an Ammonite 

 that has a more finely or more frequently incised sutural line, than 

 Pachydiscus Suciensis. 



As already stated, on pages 344 and 345, it is probable that the four 

 Ammonites from the Trent River, collected by Mr. Richardson, and 

 referred to on page 208 of this volume as Ammonites complexus, var. 

 Suciensis, specimens Nos. 3, 4, 5 and 6, may rather indicate an unusually 

 globose or subglobose form of P. Newberryanus. 



S. — Abyiormal form, in which there arc no periodic 

 constrictions on the cast of the interior of the shell. 



Shopland, near Maple Bay, Cowitchan district, about thirty miles south 

 of Nanaimo, V.I., a well preserved and nearly perfect cast of the interior 

 of the shell, about ninety-eight millimetres or nearly four inches in its 

 greatest diameter. On the outer volution of this specimen thirteen of the 

 ribs are rather larger, more prominent, and longer than the rest, and between 

 each pair of the larger ribs there are from one to four smaller ones. Two 

 similar but not quite so well preserved specime; s in the Museum of the 

 Survey v, ere collected on the Nanaimo River by Mr. Harvey in 1901, but 

 one of these shows two periodic constrictions at a short distance from the 

 aperture. 



Pachydiscus multisulcatus. (N. Sp.) 



Plate 50 ; the only figure. 



Shell inflated, but very slightly compressed at the sides ; umbilicus oc- 

 cupying about one-third of the entire diameter, its margin rounded and 

 its inner wall rather steep. Volutions increasing rather rapidly in size, 

 somewhat closely embracing, about one-half of each of the inner ones 

 being covered ; aperture nearly as wide as high, widely subovate, but 

 concavely emarginate by the encroachment of the preceding volution. 



