[I±!Ilibraryi so 





THE OTTAWA f(ATURALIST. 



Vol. XV. OTTAWA, MAY, 1901. No. 2. 



NOTE ON A SUPPOSED NEW SPECIES OF LYTOCERAS 



FROM THE CRETACEOUS ROCKS AT DENMAN 



ISLAND, IN THE STRAIT OF GEORGIA. 



By J. F. WHITKAVES. 



In 1 87 1 Mr. James Richardson, then of the Geolog-ical Survey 

 of Canada, collected a fragment of the inner whorls of an 

 Ammonite with numerous slender and finely costulate volutions, 

 a wide, open umbilicus, and rounded venter, from the Cretaceous 

 rocks at Norris Rock, south of Hornby Island, in the Strait of 

 Georg^ia. This specimen was described by the writer, referred 

 with a query to A7n7nonifes Jukesii, Sharpe, and figured, in the 

 second part of the first volume of " Mesozoic Fossils," published 

 in 1879, The type and only known specimen of A. Jukesii, it 

 may be mentioned, is a mere fragment from the "hard Chalk of 

 the county of Londonderry," Ireland, described and figured by 

 Sharpe in his monograph of the Cephalopoda of the Chalk, pub- 

 lished by the Paleeontographical Society of London in 1853. 



Much larger, more perfect and beautifully preserved specimens 

 of the same shell as the specimen from Norris Rock, were collected 

 at Denman Island, near Hornby Island, four in 1892 and three in 

 1895, by Mr. Walter Harvey, who also obtained a characteristic 

 fragment at Hornby Island in 1892. Three of these specimens 

 from Denman Island are now in the Museum of the Survey, and 

 two of them were described by the writer, under the name Lyio- 

 ceras Jukesii (Sharpe), and figured, in a paper "On some Fossils 

 from the Nanaimo group of the Vancouver Cretaceous," published 

 in the Transactions of the Royal Society of Canada for 1895. 



