XIII 



PL Y. 



Figure i. Gersemia candida, magnified. 



— 2. A polyp, magnified: a) anterior part of body; b) posterior part. 



3. Anterior part of body, with exserted tentacles, magnified (in preparing the specimen, the pinnules unfortunately 

 fell off): a) broad extremity of the thorny clubs. 



— 4. A tentacle, with its long pinnules, magnified. 



— 5. Ectodermic cells, magnified 550 times, drawn by Camera lucida. 



— 6. Entodermic cells, equally magnified, and drawn in the same manner. 



Figs. 7, 8. Spicules from the basal part of the trunk and from the trunk itself, magnified. 



Figure 9. Spicules from the basal part of a polyp, magnified, 



Figs. 10, n, Spicules from the posterior part of a polyp, magnified. 



— 12, 13. Spicules from the anterior part of a polyp, magnified. 



— 14, 15. Spindles and thorny clubs from the tentacles, magnified. 



Figure 16. Clavularia borealis, magnified: a) A polyp with the anterior part of the body retracted. 



— 17. A polyp, with retracted tentacles, magnified: a) posterior part of body (calyx); b) anterior part. 



— ■ 18. A polyp opened longitudinally, with retracted tentacles, magnified: a) short gastral filaments; b) long do.; c) gene- 

 rative products on the septula. 



— 19. Ectodermic cells, magnified 550 times, drawn by Camera lucida. 



— 20. Entodermic cells, do. do. 



21. Transverse section of the upper and outer surface of the oesophagus: a) entodermic cells, slightly modified ; b) cor- 

 puscles of connective tissue, with offshoots in the hyaline connective tissue. 

 Figs. 22, 23, 24, Spindleshaped and club-shaped spicules from the basal part, magnified. 

 Figure 25. Spindleshaped do. from the posterior part of the body, magnified. 

 Figs. 26, 27, 28. Spicules from the anterior part and from the tentacles, magnified. 

 Figure 29. A pinnule with its spicules, magnified. 



— 30. A small piece of a tentacle, covered with nematocysts (cnidiæ), magnified. 



Pl. YL 



Figure 1. Clavularia Stormi, slightly magnified: a) posterior part of the polyp-body; b) posterior part of the body, in which 

 the anterior part is drawn out and concealed; c) a posterior part exceedingly contracted. 

 2. A polyp, magnified: a) basal part, with its spicules; b) posterior part of body; c) margin of the latter; d) anterior 

 part of body, with tentacles. 



Figs. 3, 4. Spindleshaped spicules from the basal part, magnified. 



— 5, 6. Furcate and cruciform spicules from the basal part, magnified. 

 Figure 7. Club-shaped spicules from the basal part of the body, magnified. 



— 8. A peculiar spindleshaped spicule, furnished with pinnæ from the basal part, magnified. 

 Figs. 9, 10. Furcate and cruciform spicules from posterior part of body, medial part, magnified. 



Figure 11 a, b, c, d, e) spicules from the narrow transition tract extending from the posterior to the anterior part of the body, 

 magnified. 



— 12, Cruciform spicule from same locality, magnified. 



— 13. Anterior part of body with tentacles, opened longitudinally, magnified: a) small spicules: b) cruciform spicules. 



— 14. A tentacle with spicules, magnified. 



Pl. VIL 



Figure 1 



2 



— 3 



4 



5 



— 6, 



— 7 



Sympodium norvegicum covering the tube of a Sabella penicillus, natural size. 



A polyp, with its cell, and a small piece of the basal part, magnified: a) the cell; b) its free margin; c) posterior 

 part of the polyp-body; d) anterior part; e) tentacles. 

 Ectodermic cells, magnified 550 times, drawn by Camera lucida. 



Transverse section of the medial, posterior part of the body, equally magnified and drawn in like manner: 

 a) corpuscles of connective tissue; b) the muscular layer; c) entodermic cells. 



Transverse section of anterior part of body, immediately below the tentacular margin, slightly magnified: a) con- 

 nective tissue, with spicules; b) spicules on outer wall of the oesophagus; c) oesophagus. 

 Oesophagus, with its 4 series of spicules, magnified. 



A polyp; opened longitudinally; oesophagus and gastral filaments removed, magnified: a) septula on posterior part 

 of body; b) ova and ovarian capsule; c) the cell, with its spicules; d) spicules on anterior part of body; e) trans- 

 versely disposed spicules on the boundary, between the anterior and the posterior parts of the body; f) spicules 

 from the tentacles and the pinnules. 



4 



