The Ligament in the Lamellibranchia

On The Biology Of Glossus Humanus (L.) (Isocardia Cor Lam.)

“…Tellina), the cardinal teeth radiate across the hinge plate, increasing slowly in all dimensions with growth. But in G. humanus, the mantle isthmus (Owen, Trueman & Yonge, 1953) is continuously displaced posteriorly due to the effect of the tangential cqmponent on the mantle edge (Fig. 2).…”

“…The description of the hinge teeth given by Jeffreys (1863) is confusing, for the dentition of the right valve is described as that of the left and vice versa. The' tangential component also affects the anterior region of the external opisthodetic ligament (Owen, 1953), When there is no tangential component affecting the form of the valves, as in Glycymeris, growth of the mantle/shell (Yonge, 1953) anterior to the umbones takes place anteriorly, i.e. away from BIOLOGY OF GLOSSUS HUMANUS 87 the umbones.…”

“…In describing the structure of the ligament in G. humanus the nomenclature suggested by Owen et al (1953) has been used. The relationships of the mantle, ligament and valves are shown in Fig.…”

Bivalvia of the super families Pholadomyacea and Pectinacea from the permian of Eastern Australia

“…The primary ligament appears to be extended at least as far as the adductors by fusion layer, formed by the fused outer surfaces of the outer folds of the mantle margin (Owen, Trueman & Yonge, 1953), and there is an accompanying loss of pallial attachment above the adductors (Owen, 1958). Yonge (l9^a classed the siphons as 'Type A', that is formed from only the muscular inner fold of the mantle margin, and similar to those of the Nuculanidae and Tellinacea.…”

“…The following is a srjmraary based on the work of Yonge (l948a, 1953Yonge (l948a, , 1957, Owen (l958, 1959a, b ) , and Owen, Trueman & Yonge (1953).…”