iNcisuEA (scissueella) lytteltonensis. 47 



the visceral spire, showing the opening of the oviduct, od., into the 

 hinder end of the ovary, ov. x 135. 



Fig. 13. — (^. A section through the left kidney showing the reno- 

 pericardial duct, rjJ. d. Note the band of ciliated cells, cil.. on the floor 

 of the mantle-cavity opposite the opening of the left kidney, x 225. 



Fig. 14. — ? . A jjortion of a section through the left kidney showing 

 the rounded phagocytic cells, phg., which have taken uj) solid rod- 

 shaped bodies from the subjacent blood-vessel, b. v. x 1000. 



Fig. 15. — Strij)ed muscle-fibres attaching the anterior end of the 

 buccal bulb to the integument, x 1 000. 



Fig. 16. — A transverse section through the anterior filaments of the 

 left ctenidium. Note the osphradium, os., lying under the branchial 

 nerve, b.n. x 535. 



Fig. 17. — A transverse section somewhat posterior to that drawn in 

 fig. 16, passing through the posterior filaments of the left ctenidium. 

 In this and the previous figure note, d. g. r., the dorsal glandular ridges 

 of the gill-filaments. X 535. 



Fig. 18. — A transverse section through two gill-filaments of the right 

 ctenidium ; cil. c, the ciliated canal traversing the dorsal glandular 

 ridges of the filaments. X 1000. 



Fig. 19. — The left ctenidium stained and viewed from above as a 

 transparent object. X 225. 



Fig. 20. — A portion of the radula. x 800. 



Fig. 21. — Part of a transverse section passing through the anterior 

 end of the buccal bulb to show, m.f., the median dorsal fold of the 

 buccal cavity and, s. g}, the anterior salivary glands and their ducts. 

 X 535. 



Figs. 22-26. — A series of transverse sections through the right-hand 

 posterior corner of the mantle-cavity showing the relations of the ovi- 

 duct and the right reno-pericardial duct to the right kidney and the 

 pericardium, x 225. (These figures are drawn as seen reversed under 

 the microscope.) 



Fig. 27. — A cephalic tentacle showing the two multiple rows of 

 sensory papillse. X 225. 



Fig. 28. — A longitudinal section through three sens&ry papillae of a 

 cephalic tentacle. n\ pale nucleus of a supporting cell; n", deeply 

 stained nucleus of a sense-cell ; cil., cilia borne at the ends of the sense- 

 cells. X 1000. 



