THE HELIOZOA 



35 



and L. Apertures very small. Provided with a stalk. 20-30 \L. Fresh- 

 water. Elaster, Grimm. Apertures very numerous. No stalk. 20 p. 

 Freshwater. Choanocystis, Penard. Apertures provided with long funnel- 

 shaped collars. No stalk. 13 p.. Freshwater. 



Fio. 0. 



Rhaphidiophrys elcgans. Eight individuals united together by protoplasmic strands and 

 surrounded by a skeleton of half- rings. A nucleus is shown in one individual. (After 

 Jlertwig and Lesser.) 



LITERATURE. 



A very extensive list of works on Heliozoa will be found in the book by 

 Fenard (14). The following is a list of some of the priucipal books and papers 

 referred to in the text : 



1. Awerinzew, S. zookhlorellakl u Prostyeishikh (On Zoochlorellae in the 



Protozoa). Protok. St. Peterb. Obshch. xxxi. 1, No. 7 (1900), p. 322. 



2. Brauer, A. Zeitschr. wiss. Zool. Iviii. (1894), p. 189. 



3. Biitschli, 0. Bronn's Thierreich, Protozoa, 1880-82. This contains a biblio- 



graphy up to the year 1879. 



4. Cienkowski, L. Arch, inikr. Anat. iii. (1867). 



5. Crawley, S. P. Ac. Philad. 54 (1902), p. 256. 



6. Grenadier, H. Z. wiss. Zool. v. (1869), p. 259. 



7. Hertwig, R., and Lesser, E. Arch. mikr. Anat. x. (1874), Supp. 



8. Hertwig, R. Abh. k. bayer. Akad. Wiss. xix. (1898). 

 9. Test, von Haeckel (1904). 



10. Keeble, F., and Gamble, F. W. Quart. J. Micr. Sci. li. (1907), p. 167. 



11. Klebahn, H. Jahrb. wiss. Bot. xxii. (1890), p. 415. 



