PLATE XV. 



Fig. 1. Cerehratulus luu(jifij>sus, n. sp. Transverse section through the iirobosciJian sheath, a, the 

 inner longitudinal muscular layer of the body wall; pr.sn, the proboscidian sheath nerve; 

 Pr.S, the lumen of the proboscidian sheath; f, its inner epithelial lining; b, the homo- 

 geneous basement membrane of this epithelium, traversed by radial fibres and separating 

 the aforesaid epithelium from the muscular layers (an inner longitudinal, and an outer 

 circular) of the proboscidian sheath ; Gf, the gelatinous tissue between the proboscidian 

 sheath, the intestine and the body wall ; dv, the dorsal blood-vessol. 



Fig. 2. Cerehratulus marroren, n. sp. Transverse section of the proboscis, b, the ensheathiug mem- 

 brane ; a' and y', the two layers of longitudinal, /3', the layer of circular muscular fibres, the 

 latter connected crossways at two diametrically opposite points with the membrane b ; n/jd, the 

 nerve-plexus between (3' and y; E, the very high inner epithelium with smaller (f) and 

 larger (C) batteries of nematocysts. 



Fig. 3. Cerehratulus macroren, n. sp. Transverse section of the proboscis much further backwards ; 

 the proboscis is thinner, the muscular fibres (a) only longitudinal, the epithelium (£) 

 flattened, the nervous plexus replaced by two longitudinal nerve-stems N. 



Fig. 4. Cerebratidus ani/usticejis, n. sp. Head, a, from below ; b, side view. 



Fig. 5. Cerebraiuhis parkeri, n. SI). Head, a, side view ; &, from below. x li. 



Fig. 6. Cerehratulus sp. inc. Two fragments from Japan. x 2. a, dorsal view ; b, ventral view. 



Fig. 7. Gerebratulus sp. inc. Transverse section of one of the fragments of fig. 6. /, the integu- 

 ment ; a, /3, and y, the much reduced muscular layers ; iV, the lateral nerve-stems ; Int, the 

 intestinal canal and caeca, suspended in the gelatinous ground tissue Gt ; Gf, the same tissue 

 expanded between the very sparse external fibres of the muscular layer y ; PrS, the probo.s- 

 cidian sheath ; hr, the blood-vessels. 



Fig. 8. Cerehratulus sp. inc. Lateral view of the head of another specimen from Japan (Kobe). 



Fig. 9. Cerehratulus Inngifi.ssus, n. sp. Longitudinal section of the tail end. /, the integument ; 

 Int, the intestinal epithelium ; a, j3, y, the muscular layers ; npil, the nerve plexus. This figure 

 is meant to show the general aspect of the muscular layer a, more highly magnified in fig. 10. 



Fig. 10. Cerebrafulus longifissus, n. sp. The muscle-fibres of the layer a are seen to present a more con- 

 siilerable diameter in successive vertical planes, forming rings round the intestine and alternating 

 with others in which this increase in diameter is not visible. Nuclei are also more numerous 

 in the former portions than in the latter ; Ep, the intestinal epithelium ; Gt, the gelatinous 

 tissue between this and the body musculature, with bundles of radial fibres. 



Fig. 11. AriuMporus moseletji, n. sp. Transverse section of the lateral region with glandular cavities 

 (cjl), arranged along the lateral line between the dorsal and ventral musculature a, piercing 

 the circular muscular layer /3 at e, and suspended by the gelatinous tissue gt. I, integu- 

 ment ; B, basement membrane. 



Fig. 12. Anqildporus museleyi, n. sp. One of the glandular caeca, more considerably magnified, with 

 granular epithelium and flattened nuclei exteriorly, the latter belonging to the surrounding 

 gelatinous tissue. 



Fig. 13. Drepa7wp]iorusluiiIiesteri,n. sp. A section of similar glandular creca in the dorso- median region 

 of the head. 



Fig. 14. Ampldpf)rus iiiariunl, n. sp. A very unripe generative cajcum, not yet opening to the exterior. 

 P, Circular, a, longitudinal muscular layer. The crecum reaches down into the gelatinous 

 tissue, gt. 



Fig. 15. AnipJnjMrus marioni, n. sp. Ova in different stages of development. 



Fig. 16. Cerehratulus parkeri, n. sp. An ovum. 



Fig. 1 7. Drepanophonis serraticollis, Hubr. An ovum. 



Fig. 1 8. Cerehratulus sp. inc. A batch of ova from a ripe generative c;«cum of a specimen from Station 



321. The ova are surrounded by a hyaline membrane (which has erroneously been dotted 



by the lithographer) and pressed into polygonal shapes. 

 Fig. 19. Cerehratulus viacroren, n. sp. Part of a transverse section, in outline. I'rs, The cavity of the 



proboscidian sheath ; /, integument ; y, /?, the muscular layers ; N, the longitudinal nerve-stem ; 



ge.e, the generative caecum ; o, its exterior opening. The duct to this ojX'ning, whore it 



pierces the layer y, is considerably extended in bulk. 

 'Fig. 20. Amphiporus inoseleyi, n. sp. A longittulinal section through the greater part of the compressed 



(esophagus Oe, and subjacent intestinal cseca («*). 



