ACTIXOCEEATID^. 
193 
Actinoceras Breynii, ICartin, sp. 
1809. Conch. N. OHhoceratites Breynii, Martin, Petrificata Derbiensia, 
pi. xxxix. f. 4. 
? 1836. Orthoceras Breynii, Phillips, Geol. of Yorkshire, pt. ii. p. 238. 
? 1844. Orthoceras {Loxoceras) Breynii, M‘Coy, Carboniferous Lime- 
stone Foss, of Ireland, p. 8. 
1849. Melia Breynii, d’Orbigny, Prodr. de Paleont. Stratigraphiqiie, 
Yol. i. p. 114. 
1851. Orthoceras Breynii, Giebel, Fauna der Vorwelt, Band iii. 
Abth. i. p. 232. 
1855. Orthoceras (Loxoceras) Breynii, M^Coy, British Pal. Foss. fasc. 
iii. p. 567. 
1860. Loxoceras Breynii, Griffith, Jonrn. Geol. Soc. of Dublin, vol. ix. 
p. 55. 
1867. Orthoceras Breynii, Armstrong, Ymung, and Eobertson, Cat. of 
the Western Scottish Fossils, p. 59. 
1880. Orthoceras Breynii, de Koninck, Faune du Calc. Carbonifere de 
la Belgique, tom. y. p. 73, pi. xxxYiii. ffi 11, a-c', pi. xxxix. 
ffi 3, 3ft. 
Bp. Char. Shell straight. Section elliptical, the ratio of the two 
diameters being as 14 : 17. Hate of increase about 1 in 5. Sejjta 
horizontal, forming a shallow sinus on the side nearest the siphuncle, 
and arching upwards laterally. Siphuncle situated midway between 
the centre and the margin, in the line of the shorter diameter, the 
segments of which it is composed are considerably inflated between 
the septa. “ Surface (indistinct) apparently marked with fine, ob- 
tuse, transYerse strise” (^2BCoy). 
Remarl's. An excellent sketch of this species is giYen by Martin, 
and one has no difficulty in recognizing its characters in the spe- 
cimens in the Collection, Some of these haYe unfortunately no 
locality recorded against them, but there is reason to suppose that 
they are from Derbyshire. 
Horizon. Carboniferous Limestone. 
Localities. Bolland, Yorkshire ; Derbyshire ? 
Fairly well represented in the Collection. 
Actinoceras inops?, Dawson. 
1868. Actinoceras inops, Dawson, Acadian Geology, 2nd ed. p. 314, 
f. 133ft. 
Bp. Char. This small species, of which only a portion of the 
septate part of the shell is known, is remarkable for its high rate 
of tapering, Yiz. 1 in 3. 
The siphuncle is very large according to Dawson’s figure, in which 
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