40 G. LINDSTRÖM, THE ASCOCERATIDAE AND THE LITUITIDA. 
specimen shows the aperture entire. The ribs are narrow, closely set, so that six are 
contained within a length of 10 millim. "The three innermost whorls have a fine reticu- 
late ornamentation, but the longitudinal strie cease at the beginning of the fourth whorl, 
so that the three outermost whorls have only transverse strix (f, 34 a) but of two kinds, 
some larger, regularly distantiated and between them smaller, microscopically fine. 
The keel of the ventral side (fig. 33) is traversed by sharp, almost imbricated curves, 
directed backwards. 
The body chamber is extraordinarily long, occupying the entire first whorl. In the 
young specimens the body chamber is still longer occupying more than two whorls. The 
second whorl has 27 septa. The siphuncle is placed near the dorsal or interior side of 
the shell and is narrow and slender. 
Dimensions. Largest diameter 37 millim. Breadth of the largest whorl 7 millim. 
Thickness of same 8 millim. Distance between the septa 2 millim. Breadth of the 
keel 3 millim. 
The only previously known species, with which this has any affinity, is the Bohe- 
mian O. rudens (BARR. pl. 45 f. 13—24), but the more obovate whorls of this and their 
different ornamentation sufficiently distinguish them. 
