334 
SUPPLEMENT. 
species may be easily mistaken for 0. Jovellani, Tern. The septa 
are very approximate, and the interior of the siphuncle is filled from 
the centre to the circumference with radiating lamellae.” 
BemarTcs. It was justly observed by the brothers Sandberger 
that the short description given by de Yerneuil, unaccompanied by 
figures, was not sufficient to distinguish his species from triangularis ; 
but the position of the siphuncle, as we learn from the excellent 
figures subsequently furnished by Bayle, serves at once to distinguish 
Bmhi from triangularis. Were it not, however, for the ornaments 
of the test, there would be nothing by which to distinguish the 
former species from Jovellani, as de Yerneuil himself remarked, so 
that the validity of the present species must remain an open question 
until a specimen of Jovellani shall have been discovered with the 
test preserved. 
Horizon. Devonian. 
Locality. Nehou (Manche), France. 
Eepresented in the Collection by a single imperfect example. 
NOTE ON ASCOCERAS\ 
An interesting discovery has lately been made by Professor G. 
Lindstrdm, of Stockholm, which throws new light upon the structure 
of the shell of the remarkable genus Ascoceras^. The specimens 
which formed the subject of Dr. Lindstrdm’s investigations were 
found in the “ uppermost limestone stratum ” (homotaxial with the 
Upper Ludlow) of the Island of Gothland, which contains a large 
assemblage of Cephalopoda, about 200 species being known, and 
amongst these nine species of Ascoceras (including Glossoceras). 
The chief facts elicited by the study of these species are the follow- 
ing : — That the shell of Ascoceras consists of two portions, the first, 
or older, resembhng that of an Orthoceras (see fig. 51), having a 
cylindrical shell, with wide septa, and slender, tubular siphuncle, 
this stage being succeeded by a second or Ascoceras-stage, after the 
completion of which the older or Orthoceras portion became decol- 
lated or cast off ; hence its rare preservation. 
^ Die Yerstein. Nassau, 1856, p. 157. 
* See paper by Prof. G. Lindstrom in Geologiral Magazine, Decade iii. 
Yol. V. pp. 532-534 (1888). 
* Ante, p. 246. 
