20 



magnified 120 diameters at the fig. IX. d, with the cilia c. ; tb, the inside 

 ciliated funnel-body, retractile by the muscles m; p, the leather-like, 

 elastic body-tube, with the buds at b ; the fracture of the tube is shown at 

 fr. ; (a Plumatella, as the engraving IX. it. shows, I only saw three times, 

 and I have not been fortunate enough to find it again) ; oz, the oesophagus ; 

 s, the stomach with the backward recurving intestine at i ; the anus at an ; 

 the ovarium's position is at ov, with a gland-tube at g ; the spermatic par 

 tides are produced opposite from the female apparatus at ts, with ciliated 

 surface, and connected with the same gland-tube at g. Magnif. about 45 — 50 

 diam. The internal organs are only shown at one of the two branches 

 (with closed tentacles). The two arrows show the direction of the move- 

 ments of the tentacles. A Bryozoan-embryo, which moves very rapidly in 

 the water, is represented by the fig. IX. (5. Magnif. about 300 — 350 diam; tb., a 

 retractile tube with long cilia on the edges ; c, the mouth with several very 

 long hairs fl ; c, cilia around the whole body ; pg, pigment spots with longer 

 cilia. Magnif. 360 — 400 diam. This figure has great resemblance with the 

 figure of Dr. Lewis in the " Report on the Water Supply of New York and 

 Brooklyn. Croton water sediment i. Halteria grandinella ? 



Plate III. — Fig. VII. — A worm, Planaria lactea ; b, the proboscis, ex- 

 pendable and retractile by muscles ; os, the mouth ; t, tree-like branched 

 chimiferous channel (stomach) ; e, the two pigment-eyes, each with a 

 globular, glass-like body (corpus vitreum ? ) ; c, the ciiia surrounding the 

 very soft body ; ov, the two ovaria ; od, the forked oviduct ; g, the two tes- 

 ticles ; vd, vasa deferentia ; ex, geriital-porus of this hermaphrodite . 



Fig. VIII. — Hydatina senta, (a Rotatorial-worm) . os, the mouth; mx, 

 maxillary apparatus ; c, the ciliated rotatory apparatus ; gl, stomach-glands ; 

 St., the alimentary cavity ; s, segments around the chitinous body-integu- 

 ment ; ov, the two ovaria ; e, eggs ; ab, ambulacral-tubes ; abc, the two con- 

 tractile vesicles of the ambulacral system ; an, the anus ; p, the furca. (f). 



Fig. X., represents another animalcule belonging to the Rotatoria-worms 

 (family Philodina), Rotifer vulgaris, mx, the chitinous jaws ; i, the alimen- 

 tary canals, with gs, two stomach-glands (secreting chimiferous juice); oc, 

 two red-pigmented eyes on the forehead ; edge, the two ciliated edges (two 

 movable lobs) ; ov, the egg-producing cavity of protoplasmatical structure ; 

 e, two snmmer-eggs ; eb, a nearly developed embryo ; ex, the enlarged end 

 of i ; an, the anus ; ga, intestinal glands (?), or rather a muscular band 

 around ex, for removing the eggs when developed ; m, muscles ; cd, the spy- 

 glass-like appendage. 



(f) After having become drv, they will revive on being moistened. The 

 thin-shelled summer-eggs, whose position is on both sides of the alimentary 

 canal, are produced by a parthenogentical manner; the thick-shelled winter- 

 eggs, fastened on both sides of the chitinous body near the furca (exter- 

 nal), are fructified by the very small male-ones. (Snteroplea hydatinae). 



