199 



that most of the finer details of their sculpture and septation are 

 obliterated, and which therefore are not figured. 



The earlier whorls of what appears to have been a young individual 

 of the same species are partly shewn in a much smaller specimen from 

 the same locality, which has much the appearance of a small Turrilites, 

 except that its volutions are not in contact. The specimen consists of 

 a nodule of argillaceous limestone, so broken as to expose one entire 

 but exfoliated whorl, with the impression of the lower half (or more) 

 of the one which preceded it. The larger of these two whorls shews 

 no remains of either tubercles or spines, but the mould of the basal 

 portion of the upper and smaller whorls exhibits the impressions of 

 four transverse rows of spines, with three spines in each row. As all 

 the remains of spines that happen to be visible in this specimen are 

 placed apparently below the siphuncle, and as the larger examples 

 shew three tubercles below the siphuncle and one above it, in each 

 transverse row, it seems probable that in the earlier whorls there was 

 originally one spine in each transverse row, above the siphuncle, as 

 well as three spines in each row below it. 



The specimens for which the above name is proposed are similar in 

 many respects to the European type of the genus, but on the whole 

 seem to be sufficiently distinct to warrant their separation. On the 

 later volutions of the present species there appear to be invariably four 

 tubercles or nodes in each transverse row and its earlier whorls were 

 probably spinose, whereas in the later whorls of the European Turri- 

 lites Robertianus there are only three tubercles in each transverse row, 

 and its earlier volutions are represented as marked by similar tubercles, 

 though of course by much smaller ones. 



AMMONITES (Auctorum.) 



The above name being now generally and as it would seem properly 

 restricted to the three-keeled group of shells of which Ammonites 

 bisulcatus of Bruguiere is the type, can no longer be applied with pro- 

 priety to any Cretaceous species. 



One of the most satisfactory as well as one of the most recent 

 attempts at a re-classification of the great order Ammonea of Lamarck 

 is the one published by Dr. Paul Fischer in the first volume of his 

 " Manuel de Conchyliologie,"* whose nomenclature and arrangement 

 will be adopted, with one or two unimportant exceptions, in the follow- 

 ing descriptions of the various species of Ammonites collected by Dr. 

 Gr. M. Dawson at the Queen Charlotte Islands. 



* Paris, 1881. 



