352 L. F. Spath—Ammonites from Spitsbergen. 
alternans from apparently contemporaneous beds of Greenland,! 
and, on account of the single costation, also to the form referred 
to Ameboceras cf. bauhini (Oppel), by Ilovaisky, from his highest 
bed D..2 Lahusen ? refers to this ““Schwarzer Brandschiefer ”’ 
of Spitsbergen, with A. nathorsti,* as containing Aucella radiata 
and Aucella bronni, but though some of the slabs of this micaceous 
shale with Ameboceras contain isolated Aucella of the type of 
A.'‘spitsbergensis and A. reticulata Lundgren, these Avucella are 
more plentiful in other examples of this shale, not associated with 
Ammonites. 
In the finer-grained, non-micaceous shales that Lindstrom ° 
and Lundgren * mention as containing A. triplicatus' and Aucella, 
shells of the latter genus also are very abundant, but the Aucella 
mosquensis probably was misquoted for a plicate variety of A. 
pallasi. This occurs together with A. bronna Rouiller, so that a 
Kimmeridgian age (zone of Aucella bronni of Lahusen) is most 
probable. Pompeckj,° however, records Perisphinctes cf. triplicatus 
(Lindstrém), together with Aulacostephanus (and corresponding 
Aucella), thus suggesting a higher horizon in the Kimmeridgian 
(Hoplitenschichten of Lahusen) than is indicated by the forms 
of Prctonia which belong to the lower alternans beds. The Ammonite 
impressions in this black shale, characterized by its weathering to 
various colours, unfortunately are badly preserved; there is great 
resemblance to the forms of Pictonia quoted above, but also to 
Perisphinctids of the achilles—decipiens group. The primary ribs 
distinguish the forms from Rasenia, e.g. R. triplicata (Sow. in 
Damon),® or the still higher Virgatites. On the other hand, one 
example agrees very well with V. polygyratus (Trautschold) in 
Pavlow,”’ so that it appears probable that a number of horizons 
1 J. P. J. Ravn, ‘On Jurass. and Cret. Foss. from N.E. Greenland”’: 
Mus. Min. Géol Univ. Copenhague, Comm. Paléont., No. 10, 1911, p. 486, 
pl. xxxvi, figs. 1-3. 
2“ L’Oxt. et le Séquan. d. Gouv. de Moscou et de Riasan’’: Bull. Soc. 
Imp. Nat. Moscou, N.S., vol. xvii (1903), 1904, p. 273, pl. x1, fig. 2. 
3“ Ub. d. Russ. Aucellen’’: Mém. Com. Géol. St. Pétersb., vol. vii, No. 1, 
1888, p. 44. 
4 Additional examples of A. nathorstt in the Reynolds Collection come 
from the south side of Van Keulen’s Bay, Bell Sound, and from Green 
Harbour (south-west). 
5 “Om Trias och Jura- Forst. fr. Spetsbergen’’: K. Svenska Vet.-Akad. 
Handl., vol. vi, No. 6, 1866, pp. 10, 19. 
§ Loc. cit., 1883, p. 3. 
7 Sowerby’s A. triplicatus (xcii, 2) is a Rasenia ; A. triplex (cexciii, 4) and 
A. trifidus (eexcii) are Corallian Perisphinctids. 
8 In Nathorst, ‘“‘ Eine vorlauf. Mitt. v. Prof. J. F. Pompeckj ib. d. Altersfrage 
d. Juraablag. Spitzbergens’’: Geol. Féren. Férh., vol. xxxii, Heft 6, Nov. 
1910, p. 1503 (table). 
9 Supplement to the Geology of Weymouth, etc., new ed., 1888, pl. xiil, fig. 3. 
10 Btudes, ete., i, 1889, p. 60, pl. iii, fig. 3a only. Trautschold’s original 
(A. polygyratus Rein., ‘‘ Z. Fauna d. Russ. Jura’’: Moskau, 1866, p. 19, 
pl. iti, fig. 4) is quite different. 
