18 CARBONIFEROUS CEPHALOPODA OF IRELAND. 



Dublin. Another was already in that Collection, and both are figured. The dis- 

 tance of the septa, which is very considerable proportionately to the size of the 

 species, and the character of the ornamentation make this species readily distin- 

 guishable from all others. The most nearly related species are the following : — 

 Orthoceras discrepans, de Koninck, in which the septa are closer together than 

 they are in the present species ; and the ornamentation differs in having two 

 series of transverse lines, the one coarser than the other; while 0. conquestum, 

 0. salvum (described below), and 0. salutatum, all of de Koninck, have very 

 crowded septa, and the transverse lines ornamenting the surface are distinctly 

 undulating. 



Locality. — Clane, county of Kildare. 



Orthoceeas salvum, L. G. de Koninck. Plate VI, figs. 4 a, b. 



18S0. Orthocebas salvum, L. G. de Koninck. FauneCalc. Carb. Belgique (Ann. 



Mus. Roy. d'Hist. nat. Belgique, ser. Paleont., 

 vol. v), pt. 2, p. 67, pi. xli, fig. 6. 

 1896. — — A. II. Foord. Ueber die Orthoceren des Kohlen- 



kalks (Carboniferous Limestone) von Irland. 

 . . . Inaugural-Dissertation zur Erlangung 

 der Doktorwiirde . . . der Kgl. bayer. 

 Ludwig-Maximilians-Universitiit zu Miinchen, 

 p. 27. 



Description. — Shell small, straight, tapering at the rate of 1 : 10. Section 

 slightly elliptic, the ratio of the longer to the shorter diameter being as 5 : 4. A 

 fragment of the body-chamber shows upon the cast a slight constriction near the 

 aperture. Septa numerous, slightly oblique, distant from each other about one- 

 fifth of their own diameter. Siphuncle apparently slightly excentric. Test 

 covered with extremely minute, regular, wavy, transverse lines, eight or nine of 

 which occupy the space of 1 mm. Faint transverse depressions occur at rather 

 regular intervals, giving an appearance of serial arrangement to the lines. 



Size. — The most complete specimen obtained is 72 mm. in length (PI. VI, 

 fig. 4 a). 



Affinities. — This species resembles 0. discrepans, de Koninck, in its form, but 

 it is distinguished therefrom by the fineness and the wavy character of its 

 ornamentation. From 0. salutatum it differs in its more rapid rate of tapering 

 and central siphuncle. 



Locality. — Doohyle, near Rathkeale, county of Limerick. 



