Girdle-fissure with the teeth, seen from the left side. Fig. 5. _Conchidium leptæna_, n. sp., × 800 1722 A single tooth with its base. Fig. 6. _Conchidium thecidium_, n. sp., × 300 1721 Lateral view, from the left side. In the oral part of the shell-cavity the dark phæodium, in the aboral part the central capsule with two nuclei (a dorsal and a ventral). Fig. 7. _Conchidium argiope_, n. sp., × 300 1722 Oblique oral view (half from the anterior, half from the left side). Fig. 8. _Conchidium argiope_, n. sp., × 300 1722 Dorsal valve, from below. Fig. 9. _Conchidium argiope_, n. sp., × 600 1722 A piece of the valve margin, with four teeth. Fig. 10. _Conchonia diodon_, n. sp., × 200 1723 Lateral view, from the left side. In the anterior part of the shell-cavity the dark phæodium, in the posterior part the central capsule with the nucleus. The two valves are connected at the posterior hinge by a ligament (to the right in the figure). Fig. 11. _Conchonia diodon_, n. sp., × 400 1723 Mouth of the shell, with its two lips, seen from the oral pole. Fig. 12. _Conchonia diodon_, n. sp., × 400 1723 A piece of the valve-margin, with four teeth. Fig. 13. _Conchonia triodon_, n. sp., × 300 1724 Ventral valve, seen from the lower face. Fig. 14. _Conchonia triodon_, n. sp., × 300 1724 Dorsal valve, seen from the left side. Fig. 15. _Conchoceras caudatum_, n. sp., × 300 1727 Lateral view, from the left side. Fig. 16. _Conchoceras cornutum_, n. sp., × 200 1728 Lateral view, from the left side. [Illustration: 1.-14. CONCHIDIUM, 15. 16. CONCHOCERAS.] PLATE 125. LEGION PHÆODARIA. Order PHÆOCONCHIA. Family CONCHARIDA. Fig. 1. _Conchopsis aspidium_, n. sp., × 150 1726 Lateral view, from the left side. Fig. 2. _Conchopsis aspidium_, n. sp., × 300 1726 The hinge of another specimen, in which the two valves are connected by a ligament (as in figs. 8 and 9, Pl. 123). Fig. 3. _Conchopsis orbicularis_, n. sp., × 200 1725 Lateral view, from the left side. Fig. 4. _Conchopsis navicula_, n. sp., × 150 1727 Lateral view, from the right side. In the lower (posterior) half of the figure is visible the central capsule with its dark nucleus, in the upper (anterior) half the phæodium with two broad sagittal wings. Fig. 5. _Conchopsis navicula_, n. sp., × 400 1727 Three single pores with their hexagonal external frame and the dilated internal ovate or ampullaceous channel.