PLATE VII. 



Fig. 1. Eupolia australis, n. sp. Diagram of a section through the posterior part of the oesophageal 

 region. Ps, proboscidian .sheath with underlying dorsal blood-vessel; lis, lateral blood- 

 spaces, continued backwards, but not much further than the oesophageal region ; bv, ventral 

 blood-vessels; Oe, cavity of the oesophagus; Nst, lateral nerve-stems; E, outer integumentary 

 layer. 



Fig. 2. Eupolia australis, n. sp. Section of the body-wall about in the same region as the diagram of 

 fig. 1, and in the vicinity of the left ventral blood-vessel. E, outer epithelial layer with 

 unicellular glands; B, its (secondary) basement membrane; ef, scattered longitudinal and 

 circular fibres beneath this ; gi, subepithelial glandular layer ; dim, outer longitudinal 

 muscles, as yet very far from being a compact layer ; cm, circular muscular layer ; Urn, inner 

 layer of longitudinal muscles ; ct, cellular coating of the circumcesophageal blood-space. 

 (Between dim and gi the reference letter Bet, indicating the primary basement tissue 

 (ef. figs. 3, 5), should be inserted. 



Fig. 3. Eupolia australis, n. sp. Section of body-wall of the same specimen, very much further back. 

 Lettering as in fig. 2. Moreover, Bet, fibrous connective tissue (primary basement 

 membrane) between gi and dim; Je, epithelium of the intestine; bv, left ventral blood- 

 vessel. The outer longitudinal muscular layer is thinner, but at the same time much more 

 compact than it was in the section of fig. 2. The blood-vessel and its surroundings, as well 

 as the intestinal epithelium, are only represented diagrammatieally. 



Fig. 4. Eupolia giardii, n. sp. A transverse section through the dorso-median (medullary) nerve- 

 stem (dmN). The nerve-fibres are transversely cut; the nuclei are distinct. NL, the 

 nervous layer, continuous with the median stem ; dim, outer longitudinal muscular layer 

 with a considerable amount of gelatinous connective tissue (ct) between the separate 

 bundles. 



Fig. 5. Eupolia giardii, n. sp. Portion of a transverse section through the body-wall (ef. PI. VI. 

 fig. 9). Only a small portion of the very thick circular muscular layer cm is here represented. 

 Lettering as in figs. 2 and 3. Nst, longitudinal nerve-stem : Nep, two radial ducts of the 

 nephridia leading outwards, one of them opening to the exterior at ne.o. The outer 

 longitudinal muscular layer is far from compact, the secretion of the sub-epithelial glands 

 gi can be traced piercing the layers, cf., B and E. 



Fig. 6. Eupolia nipponensis, n. sp. The outer ciliated epithelium (E) and unicellular glands (" Schleim- 

 stabchenzellen ") secreting their product (u.g) to the exterior, supported by the basement 

 membrane B. 



Fig. 7. Eupolia australis, n. sp. Longitudinal section in the posterior region of the body-wall, to show 

 the generative ducts (gd) leading from the. generative sacs (gon) outwards and piercing the 

 muscular layers (Urn and an) above the nerve-stem (Nst). 



Fig. 8. Eupolia giardii, n. sp. The sub-anal nervous commissures in a horizontal section. J, cavity 

 of intestine ; Je, epithelium of the same ; N, N', the right and left longitudinal nerve-stem 

 communicating by the transverse commissure; E, external epithelium. 



Fig. 9. Eupolia delineata, n. sp. Longitudinal section through the body-wall. Lettering as in figs. 2 

 and 3. efp, the external longitudinal and circular fibres that belong to the integument and 

 have the pigment between them. 



Fig. 10. Eupolia delineata, n. sp. Section of the proboscidian sheath. Ps, the cavity of the sheath 

 lined by cells which are again encircled by a very attenuated circular layer ; bl, blood-spaces 

 outside of the proboscidian sheath ; cts, strings of connective tissue by which the proboscidian 

 sheath is suspended to the body-wall. 



Fig. 11. Eupolia nipponensis, n. sp. Transverse section through the nervous layer (Nl). Nuclei are 

 found imbedded in the nerve-substance and fibrous nerve strings stretch out from it radially 

 at different points, olm and cm, the muscular layers. 



Fig. 12. Eupolia nipponensis, n. sp. The oesophageal wall, in transverse section, cm. and Urn, mus- 

 cular layers of body-wall ; bs, blood-space inside of these. The wall of the oesophagus is 

 constituted of an inner ciliated epithelium Je, a basement layer B, and a thick layer of 

 glandular cells Jm. 



