22 G. LINDSTRÖM, THE ASCOCERATIDA AND THE LITUITIDAZ. 
of the shell being there 9 millim:s. On the dorsal side of the siphuncle the septa join 
each other in the usual way. 
The siphuncle is placed near the ventral side. Its first element is large and ovate. 
In the three upper elements the lining walls are wanting and probably dissolved away. 
The siphuncle is rather wider at the top than at its base. 
Length of the shell 18 millim:s, largest diam. 12 millim:s, the shorter one 10 millim:s. 
This species differs from the nearly related Asc. cochleatum through its more plump 
and obese shape, the different outlines of the dorsal and ventral sides and through the 
more numerous and imbricating, transverse lines. 
It has some resemblance with Asc. Keyserlingi BARR. as to the ornamentation, but 
it is else quite different. 
3. Ascoceras fistula n. 
Pl; I. f. 11—39, pl KU dB AL EE 
Distribution. This species is not seldom found in the uppermost stratum of Got- 
land (h.), around Slite, at Samsugn and Klints in Othem. A small slab from Slite, figured 
on Pl. I f. 17, and belonging to the Mineralogical Cabinet of the University of Upsala con- 
tains no less than 20 specimens of this species. 
1. The Nautiloid stage of growth, Pl. I figs. 28—39. 
Shell very narrow, cylindrical, slightly curved, increase of width so slow that in a 
fragment having 34 millim:s in length, the width at the upper end has increased only to 
4 millim:s from 2 millim:s in the lower end. The initial shell has not been found, there 
being always a truncature. A fragment, fig. 36, has an oval section near the truncature, 
as well as on a distance of 4 mm. from it, while it is quite circular near the broken 
aperture. Its total length is 9 mm. Other specimens have a quite circular section in 
their whole length. The inferior apex is a little swollen or bent in a different direction. 
The ornamentation consists of narrow, transverse wrinkles, arched downwards on 
the ventral side. They are often arranged in annular folds resembling those which occur 
in several Orthoceratites, as O. annulatum; and as often, as with them, evanescent. Seen 
in a longitudinal section the fine strix on these wrinkles have a serrulated appearance. 
The septa are regularly concave, somewhat oblique, higher on the dorsal side and 
slanting toward the ventral. They are much crowded in small specimens and become more 
and more distantiated the longer the shell grows. Thus for instance in a specimen 40 
millim:s in length and 4 millim:s when widest there are in all 27 septa and of these 14 
are situated on a length of 13 millim:s and the other 13 on a length of 21 millim. 
The distance is in the beginning about one millim. between each septum, then it is a 
little irregularly increased, the space being now and then shortened till it rises to near 
3 millim:s, and becomes at last so much as 7 mm.; the greatest distance between two 
septa being 11 millim:s. The shape of the septum is then also changed, it is not quite 
so oblique and forms around the siphunele a distinct neck. The first septum next the 
oldest truncature is distant from this end nearly as much as the space from the said 
septum to the third septum. 'The necks of the septa are short. The siphuncele is situated 
