TRIASSIC FISHES FROM SPITZBERGEN 
XI 
plant-bearing horizon, discovered in 1909 in the upper , series above the black shales, 
was of Rhaetic age. In addition he points out the incorrectness of Mojsisovics’s statement 
that the fossils from series of black shales as a rule are derived from limestone, and 
finally he also quotes the preliminary results at which Bohm had arrived in his investiga¬ 
tions of the evertebrate material from Bell Sound. Bohm had then distinguished: 
Upper Trias: with Pseudomonotis spitzbergensis Bohm, Aviculopecten mriiani Bohm, 
Avicula cfr. sola Oberg, Pseudomonotis ochotica Kays. 
Middle Trias: » Halobia de geeri Bohm, Lingula lindstromi Bohm, Monotis albertii 
Goldf. sp. var. 
Lower Trias: » Meekoceras (Gyronites) nathorsti Bohm, Posidonomya sp. and Lin¬ 
gula sp. 
In 1911 Stolley, who the previous year had had the oppertunity of taking- part in 
the excursion of the Eleventh International Geological Congress to Spitzbergen, published 
an important paper on the Trias strata at Middelhook in the Ice Fjord. He came to 
the conclusion that the fauna described from the Posidonomya shale was not a unit, but 
that it came from two different horizons. Thus, according to his observations, Ceratites 
costatus Oberg belongs to a horizon above the Posidonomya shale, and in his opinion the 
same is true of C. vega Oberg and C. lindstromi Mojsisovics. The Posidonomya shale 
proper is characterized, he says, especially by the smooth Arctoceras species, Meekoceras 
(Gyronites) aplanatum White and a form resembling Prionolobus waageni Hyatt et Smith, 
i. e. species that support the view that in this case we are most probably concerned 
with deposists of lower Triassic age. 
In connection with this he emphasizes the view that the Posidonomya bed did not 
represent the bottom of the Triassic deposits in the Ice Fjord district, but added, 
however, that no details could be established with regard to the boundary between 
the Permian and the Triassic. He also mentions that Prof. W. Salomon found in the 
upper part of the «Permian» a bone-bed, which, as we shall see below, is of no little 
interest from a stratigraphical point of view. 
In a horizon situated somewhat above the Daonella beds he was able to ascertain the 
occurrence of some Nathorstites species, including, among others, probably N. lenticularis 
Bohm. This, he holds, makes it possible to conclude (p. 120) «dafl das Narthorstiten- 
Niveau am Middlehook Spitzbergens dem Schieferniveau mit N. lenticularis J.. Bohm am 
Urdberg der Bareninsel entspricht und dal 3 der fossilreiche sandige Myophorien-Horizont 
nur den oberen, auch am Kap Thordsen vorwiegend sandigen, aber fossilarmeren Schichten, 
mit denen er Lingula polaris , Lima spitzbergensis und Pecten Oebergi gemeinsam hat, zu 
parallelisierenist.» And at another place (pp. 117—118) he adds: «Die Vermutung Nathorst’s, 
dafi die untersten 140 m dunkler fossilleerer Schiefer am Urdberg usw. der Bareninsel ihren 
Platz zwischen den Daonellen-Schichten und dem Lingula-Sand stein Spitzbergens haben 
mochten, kann also nicht zutreffen; vielmehr miissen erstere den tieferen Triasschichten 
vom Kap Thordsen entsprechen und konnen nicht obertriadischen, sondern nur mittel- 
J ) This is apparently the flat «Ceratites» form mentioned bv Wiman (1910, p. 127). 
