180 SYDNEY J. HICKSON AND J. T. WADSWOETH. 
24. Miirtin, C. H. — “Some Observations on Acinetaria,” ‘ Quart. Jonrn. 
Micr. Sci.,’ 53, 1909, p. 353. 
25. Perez, Cli. — "Sur un Acinetien Noiiveau,’ ‘ C.R. Soc. Biol.,’ 1903, 
p. 98. 
26. Sand, R. — ‘ Etude nionograpliique des Infusoires tentaciiliferes,’ 
Brussels, 1901. 
27. Stein, Fr. — ‘ Der Organismus der Infusionstliiere,’ Leipzig. 1868. 
EXPLANATION OF PLATE X, 
Illustrating the memoir by Messrs. Hickson and Wadsworth 
on Dendrosoma radians. 
Lettering. 
A. Arms of Dendrosoma. chr. Chromatin granules, c.v. Contractile 
vacuoles. D. Swollen end of the arm of Dendrosoma in tig. 30. 
E. Eujilotes. Rp. Epistylis. y. Gemmula in lirood-pouch. 31. Mega- 
nucleus. 31.y. Meganucleus of gemmula. m. Micronucleus. 0. Out- 
line of gemmula in fig. 19. s. Sucker, sf. Stream of food-particles. 
f. Tentacle of Urnula. Tr. Trichophrya in fig. 45. 
Figs. 1-7. — Illustrating the free-swimming gemmula of Dendrosoma 
and its development after fixation. 
Fig. 1. — Side view of the free-swimming gemmula, showing the 
band of several rows of cilia and four of the peripheral 
contractile vacuoles. X 250. 
Fig. 2. — Surface view of a gemmula immediately after fixation. 
Tlie meganucleus (31.) has an amoeboid form. 
Fig. 3. — Gemmula as seen about thirty minutes after fixation, 
showing the suckers (s.) that have begun to sprout out 
from the general surface. Cilia are still present but 
comparatively few in number. 
Fig. 4. — Young Dendi’osoma two hours after fixation. 
Fig. 5 . — Young Dendrosoma three hours after fixation. 
Fig. 6 . — Young Dendrosoma five hours after fixation. 
Fig. 7. — Young Dendrosoma one day after fixation. All the 
suckers are now confined to the extremity of the single arm. 
Fig. 8. — Section through a part of the stolon of a Dendrosoma showing 
a cluster of six micronuclei (»i.). 
