176 
N-AUTILOIDEA. 
septa and the rapid rate of tapering separate A. suhconicum from 
other species with which it might be compared. 
Horizon. Upper Ludlow. 
Localities. Llanfrechfa, near Newport, and Horeb Chapel, Mon- 
mouthshire. 
Represented by two imperfect specimens in the Collection, pre- 
sented by J. E. Lee, Esq., E.S.A., F.G.S. 
Actinoceras xmmnmlarium ?, Sowerby, sp. 
1839. Orthoceras nummularium, Sowerby, in Murchison’s Sil. Syst. 
p. 682, pi. xiii. f. 24. 
1872. Actinoceras nummularimn, Salter, in Murchison’s Siluria, 5th 
edition. Appendix, p. 534, pi. xxvi. f. 5. 
1875. Orthoceras nummularium, L. Mallada, Sinopsis de las Especies 
Eosiles en Espana, in Bol. Com. del Mapa Geol. de Espaha, tom. 
hi. cuad. 1 & 2, p. 25. 
1880. Orthoceras nummularium ?, Angelin & Lindstrom, Fragmenta 
Silurica, p. 6, tab. viii. ff. 4, 5. 
1885. Orthoceras nummularium ?, Lindstrom, List of the Foss, of tlie 
Upper Silurian Formation of Gotland, p. 6. 
8^. Char. These are imperfectly known ; Sowerby describes them 
as follows : — “ Conical ?, smooth ? ; septa very numerous, very 
convex, ^ their diameter apart ; siphuncle large, inflated between 
the septa to about three times its own diameter and ^ the diameter 
of the septum. Diameter about 4 inches.” 
HemarTcs. A large fragment from the Silurian of Norway, con- 
sisting of four or five septa, agrees fairly well with the above de- 
scription, though the siphuncle is somewhat larger proportionally 
than that of Sowerby’s type. The septa are distant about ^ the 
diameter, so that the bulbs of the siphuncle have a depressed, num- 
muloidal form, which, added to the closeness of the septa, distin- 
guishes this species from A. cochleatum. 
The measurements of the Norwegian specimen in the Collection 
are : — length 2 inches, greatest diameter inches. 
A fragment of a large beaded siphuncle from Usk may also belong 
to this species ; but it is too imperfect to warrant any confident 
statement regarding its affinities. 
Horizon. Bed 8 i ( = Wenlock ?). Ludlow (the British specimen). 
Localities. British. Usk, Monmouthshire. — Foreign. Norway. 
Represented by two imperfect specimens. 
Actinoceras Blakei, sp. nov. 
1882. Orthoceras {Actinoceras) cochleatum, Blake, British Foss. Ceph. 
pt. i. p. 161, pi. XV. ff. 7, 8. (Not of Schlotheim.) 
