24 
DEVONIAN FAUNA. 
3. CoNOOARDiuM PUGNANS, JFUdhoviie, sp. PL II, figs. 4, 4 a — c, 5, 6 a. 
1840. Cardixjm ALiroEME, var. a, Ooldfuss (pars). Petref. G-erm., vol. ii, p. 213, 
pi. cxlii, figs. lA — d (only). 
? 1853. — — Sandherger. Verst. Rhein. Nassau, p. 257, pi. xxvii, 
figs. 6, 6 a — d. 
1853. — — Steininger. Geogn. Beschr. Eif'el, p. 51. 
1889. Pleuroehtnchus pugnans, Whidhorne. Geol. Mag., dec. 3, vol. vi, p. 79. 
Bescriftion. — Shell small, very elongate, equivalve, convex, subconoidal behind, 
truncated and rostrated in front. Umbo direct, incurved, rather prominent, 
proximate, situated near the anterior side and truncated anteriorly. Hinge-line 
very long, straight, slightly sunk below the rounded superior margin. (Rostrum 
unseen in any specimen.) Anterior margin horizontally produced above to form 
the rostrum, and long, straight, and nearly perpendicular below. Inferior and 
posterior margins forming one oblique and nearly straight line, which becomes a 
little arched as it meets the hinge -margin. Anterior cordiform slope very large 
and nearly flat, slightly elevated in the centre, extending to the lowest point of 
the shell ; covered by very low, fine, concentric, rounded, close ribs, of which the 
outer are truncated superiorly by the carina. Anterior keel acute, sometimes 
rather sigmoid, reaching to the extreme antero -inferior corner. Median region 
very narrow, oblique, slightly convex, bearing only three or four unequal ribs. 
Median keel undeveloped. Posterior slope rather broad and shallow. Posterior 
region elongated, slightly convex. Ribs of the median and posterior regions 
coarse, low, and about their own widths apart, springing from the umbo 
and the part of the hinge-margin immediately behind it. The whole surface 
covered by very numerous, close, microscopic threads. Greatest depth of the 
shell on the anterior keel. Gape of the supero-posterior edge narrow and 
rather long. 
Size. — Length 10 mm., breadth 8 mm., depth 6 mm. 
Locality. — Lummaton. There are eight specimens in my Collection and one 
in the Woodwardian Museum. 
Bemarlcs. — The distinctive characters • of this species are its transverse 
conoidal shape, its very minute and close concentric threads, its very large 
anterior slope with very flat and slightly marked ribs, and the few unequal ribs 
of its median region. There appears to have existed an outer layer of shell ; 
it is generally absent, but almost entirely masks the ribs on the anterior side 
when it is present. 
This form appears to agree exactly with one of the shells figured as Cardium 
