NAUTILIDJE. 
137 
is characteristic of the Miischelkalk formation of the Alps, and is 
on its part again intimately connected with several Upper Triassic 
species. Another branch, which also very likely takes its origin 
from the same series of forms, is that composed of Nautilus Hoer- 
7iesi, Stache, N. criuv, Stache, N, Sebedinus, Stache\ out of the 
Bellerophon-limestones of the Alps ; whilst Nautilus fugax^ Mojs., 
recalls again more vividly the form of the shell as it is exhibited 
by the [geologically] older species, Nautilus Trautscholdi, Waagen, 
N. transitorius^ Waagen, or N. Wynnei^ Waagen". 
“ A species which must also very likely be considered as forming 
part of the group of Nautilus Trautscholdi, but which is somewhat 
aberrant in its development, is Nautilus latissimus ^ , Waagen, out of 
the very top beds of the Productus-limestone formation of the Salt- 
Range. To this species Nautilus Falladii, Mojs.'^, out of the Alpine 
Muschelkalk, seems to be rather nearly related. 
“With these forms, however, the number of species belonging to 
the Tuherculati is yet far from complete. A great many shells be- 
longing to this group have been described from American localities, 
but all of them seem to belong to developmental series entirely 
different from those just pointed out among the European and 
Asiatic species. Only Nautilus occidentalis, Shumard^ (non Hall), 
bears a close resemblance to N. Trautscholdi, Waagen, and might 
belong to the same developmental series.” 
To this series (Pleuronautilus) may be added the following 
species: — Nautilus {Discites) inopinatus, HalU, from the Upper 
^ “Beitrage zu Fauna der Bellerophonkalke Slldtirols,” in Jalirb. cl. k.-k. 
Reichsanst. 1877, Band xxvii. p. 271. 
- Mem. Geol. Surv. India — Palo3ont. Indica, ser. xiii. Salt-Range Fossils, 
Cephalopoda, 1879, vol. i. pp. 53-55. 
3 Ibid. p. 56. 
“ Beitrage zur Kenntniss der Cephalopoden-Fauna des alpinen Musehel- 
kalkes,” in Jabrb. der k.-k. geol. Reichsanst. 1869, Bd. xix. p. 588, Taf. xviii. f. 3. 
There appears to be some mistake on the part of Dr. Waagen in comparing his 
species N. latissimus with N. Talladii ; the latter is a very narrow, laterally 
compressed form, with the whorls much higher than wide, which is exactly the 
reverse of the former species. Probably Dr. Waagen intended to refer to 
N. Tintoretti, Mojs. (Taf. xix. of the above memoir), which does resemble 
N. latissimus. 
There is no species of this name described by Shumard. The species 
referred to is no doubt the Kautilus occidentalis of Swallow (non Hall), Trans. 
Acad. Sci. of St. Louis, 1858, vol. i. no. 2, p. 196 (no figure). The description 
of this species appears to justify Dr. WaageiTs comparison of it with Traut- 
schold’s species (A. tuber cidatus'), though the latter was described from an 
imperfect cast only. 
® Geol. Surv. of New York, 1879, Palaeont. vol. v. pt. ii. p. 426, pi. cx. 
ff. 1, 2. 
