XAUTTLID^. 
185 
separated, imbricating, transverse striae, which form a row of nodes 
on the prominent borders of the periphery. These striae rise in a 
gentle, forwardly directed curve from the umbilicus, and are then 
bent sharply forwards near the periphery. The position of the 
siphuncle is unknown. 
Remarhs. This species probably comes nearest to Nautilns Sauperi, 
Fr. V. Hauer \ but is distinguished therefrom by its strongly marked 
periphery and the ornaments of the test : from N. cfaleatm^ Mojsi- 
sovics^, it differs in its much broader form, as well as in the orna- 
ments of its test. 
Horizon. Upper Muschelkalk. 
Locality. Hallstadt. 
Represented in the Collection by one young example. 
Nautilus Sauperi, Ur. v. Hauer. 
1846. Nautilus Sauperi, v. Hauer, Cephalopoden des Miischelinarmors 
von Bleiberg in Karnten, Haidinger’s Naturwiss. Abbandl. Band i. 
p. 26, Taf. i. ft’. 1-4. 
1847. Nautilus Sauperi, v. Hauer, Cephalopoden von Aiissee, Hai- 
dinger’s Naturwiss. Abhandl. Band i. p. 261, Taf. viii. ft’. 4, 5. 
1866. Nautilus Sauperi, Dittmar, Zur Fauna der Hallstiidter Kalke 
(geogn.-palaont. Beitriige, Band i. Heft ii/j.), p. 642. 
1873. Nautilus Sauperi, Mojsisovics, Das Gebirge um Hallstatu 
(Abhandl. der k.-k. geol. Reichsanst. Band vi.), p. 28, Taf. xiv. 
ft. 5 a, 5 b, 6; Taf. xv. ft'. 1, a-c. 
1882. Nautilus Sauperi, Mojsisovics, Die Cephalopoden der Mediter- 
ranen Triasproviuz (Abhandl. der k.-k. geol. Reichsanst. Band x.), 
p. 283. 
Sp. Char. Shell somewhat inflated, flattened on the sides, narrowly 
rounded on the peripjhery in the young shell, but truncated in the 
adult. The greatest width of the whorls is just above the umbilical 
region. The narrowing of the shell towards the periphery gives the 
whorls a subtriangular section. The umbilicus is closed. The 
septa are rather app^roximate, the sutures forming a shallow sinus 
on the sides of the shell and arching strongly forwards : almost 
straight upon the periphery. The siphuncle is situated below the 
centre. The test is ornamented with fine lines of growth crossed by 
fine and regular longitudinal lines. 
Remarks. The remarkable character in this species is the change 
in the form of the periphery, which is rounded in the young shell 
^ Neue Oeph. v. Hallstatt und Aussee, in Haidinger’s Naturwiss. Abhandl. i. 
p. 261, Taf. viii. ff. 4, 5. 
^ Deis Gebirge um Hallstatt (Abhandl. der k.-k. geol. Reichsanst. Band vi.), 
p. 26, Taf. xii. ff. 1 a, 1 h ; Taf. xiii. ff. 1, 3. 
