AFFINITIES OF KCHIUKUS LTNICINCTUS. 



97 



Reference Letters. 



m.h., basal muscle between the setoe. 



m c, circular muscle. 



m.l., longitudinal muscle. 



in.o., oblique muscle. 



n., ventral nerve-cord. 



lie., nuclei. 



?«./., lateral nerve. 



nu., nucleus. 



o., ova. 



o. (fig. 21), aperture. 



(I.S., segmental organ (vcsi<de). 



p. (fig. 1), papilhe. 



p., ])(.'ritoiicum. 



ph., ])rohoscis. 



})h., })liarynx. 



pp., granular protoplasm. 



v., rectum. 



s., secretion. 



s.a., anterior seta. 



s.d., dorsal sinus. 



s.ni., mesenteric strands. 



.t.p., posterior seta. 



S.V., ventral sinus. 



t.a., ordinary tissue with fibres. 



t.c., connective tissue. 



t.p., so-called '' glandular " tissue. 



v., cavity of vesicle. 



v.a., anal vesicle. 



V.C., ciliated ventral surface. 



w., body-wall. 



SECOND SERIES. — ZOOLUGY, VOL. VlII. 



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