SUPPLEMENT. 
333 
Kate of iucrease about 1 in 5. Septa numerous and very approxi- 
mate, varying in their distance apart from 2 to 2| lines, ’svhere the 
diameter of the shell is 2| inches. On the flattened side of the 
shell (the base of the triangle) the sutures form a wide and shallow 
sinus, and arching upwards on either side upon the lateral angles 
they bend slightly backwards and then forwards upon the convex 
side of the shell (the apex of the triangle). Their course is in fact 
precisely similar to that which has been described in the sutures of 
Jovellania triangularis. The siphuncle is proportionately large and 
is filled with radiating deposits ; it is situated nearly midway be- 
tween the centre and the margin of the shell upon the convex side, 
being thus exactly on the opposite side to that in which it is found 
in J. triangularis. Xothing is known either of the body-chamber 
or of the test. 
Remarlcs. This species offers at first sight a singular resemblance 
to Jovellania triangularis., d’Arch. & de Yern., sp., but it is at once 
distinguished by the position of the siphuncle. Dr. Xayser, in an 
important memoir entitled “ Die Orthocerasschiefer zwischen Bald- 
uinstein und Laurenhurg an der Lahn,” ^ observes that “it is not 
improbable that Maurer’s 0. Ruphacliense {Rupiohaclii) is founded 
only upon a weathered and distorted example of our species ” \Jovel- 
lani~\. It may be mentioned that Earrande gives a very minute 
description of the crystalline deposits which fill up the siphuncle in 
the present species 
Horizon. Lower Devonian. 
Locality. Gijon, District of Terrones (Asturias), Spain. 
Kepresented in the Collection by a very good specimen, which was 
presented by S. P. Pratt, Esq. 
Jovellania Buchi, de Yerneuil, sp. 
1850. Orthoceratites Biichii, de Yerneuil, Bull. Soc. G^ol. de France, 
ser. 2, vol. vii. p. 778. 
? 1877. Orthoceras Buchi, (Ehlert, Bull. Soc. G4ol. de France, ser. 3, 
vol. V. p. 585. 
1878. Jovellania Buchi, Bayle, Explication de la Carte Geol. de France, 
vol. iv. Atlas, pi. XXXV. ff. 1-3. 
Sp. Char. This species is thus briefly described by de Yerneuil : — 
“ Test ornamented with transverse annulations ; siphuncle lateral, 
a little inflated as in Ormoceras. When the test is removed, this 
^ Jahrb. der Konigl. Preuss. geol. Lanclesanst. und Bergakad. f. d. Jahr 
1883, p. 42 (1884). 
^ Syst. Sil. de la Boheme, vol. ii. Texte v. 1877, p. 1273. 
