PLATE XLIX. 



Figs. 1-6. Discalia medusina, n. sp. (p. 46). 



Fig. 1. Basal view of the medusiform octoradial conn (from the inferior or subumbrellar face). The 

 central siphon, with an octolobate mouth, is surrounded by a corona of eight palpons which 

 bear numerous small medusiform gonophores on their basal pedicle. A corona of eight simple 

 perradial tentacles, bearing a terminal cnidosphere, is placed between the palpons and the 

 octolobate limbus umbrella;, which is beset with a band of glands. 



Fig. 2. Exumbrella (apical view of the corm). po, Central stigma ; pe, corona of eight peripheral stigmata ; 

 nu, the eight marginal lobes ; t, tentacles. 



Fig. 3. Lateral view of the corm, in profile; the tentacles (t) are bent downwards, po, Central stigma; pe, peri- 

 pheral stigmata ; uu, margin of the flat octolobate umbrella ; 17s, gonopalpons ; g, gonophores ; 

 sa, central siphon; so, its mouth. 



Fig. 4. Meridional section through the same corm. pli, Central air-chamber of the pneuniatocyst ; pq, radial 

 air-chamber ; f, tentacles ; uc, centradenia ; st, gastrobasal plate. Other characters as above. 



Fig. 5. Meridional section through the pneumatocyst alone, ph, Central chamber ; po, its stigma ; pq, two 

 of the eight radial air-chambers ; pie, their stigmata ; pt, trachea;. 



Fig. 6. Vertical section through the limb of the umbrella (mm), cr, Radial canal ; as, circular canal ; 

 us, marginal muciparous gland. 



Figs. 7-12. Disconalia gastroblasta, 11. sp. (p. 48). 



Fig. 7. Exumbrella (apical view of the umbrella, from above), with the octoradial system of the superficial 

 exumbrellar canals. Eight perradial main vessels arise from the small ring which surrounds the 

 apical stigma, and branch dichotomously. Their anastomosing branches unite in an octagonal 

 coronal vessel, from which the simple peripheral radial canals of the limb arise. The octolobate 

 margin is beset with a corona of glands. 



Figs. 8, 9. Octoradial chamber-system of the air-filled pneumatocyst ; fig. 9, superior or apical view (right 

 half of the figure) ; fig. 8, inferior or basal view (left half). The central air-chamber is sur- 

 rounded by a regular corona of eight interradial air-chambers (pq), and these by a peripheral 

 octolobate corona which is composed of numerous concentric ring-chambers (pk). pe, Stigmata 

 of the upper face ; pt, trachea; of the lower face ; pg, interradial pneumothyra; (pori communicantes). 



Fig. 10. Apical view of the octagonal centradenia (from above), with the brown "liver-star," or the system of 

 eight radial, dichotomously branched hepatic vessels. 



Fig. 11. Horizontal transverse section through the basal portion of the central siphon (sa), and the sur- 

 rounding centradenia (uc). The octolobate margin of the umbrella exhibits the transverse 

 sections of the basal portions of the tentacles (in a double row). 



Fig. 12. Horizontal transverse section of the umbrella, somewhat above the plane of fig. 11. In the centre is 

 visible the half of the gastrobasal plate (with four gastral ostia). cm, Hepatic canals. 



