Phylum Protoplasta [199 



Order Tripyleen Hertwig Org. Radiolar, 133 (1879). 



Order Phaeodaria Haeckel in Jenaische Zeitschr. 15: 470 (1882). 



Legion Phaeodaria and orders Phaeocystina, Phaeosphaeria, Phaeogromia, and 

 Phaeoconchia Haeckel in Rept. Voy. Challenger Zool. vol. 18 (1887). 



Order Tripylea Doflein. 



Suborder Tripylaria Minchin Protozoa 256 (1912). 



Suborder Tripylea Kudo Handb. Protozool. 263 (1931). 



Suborder Tripylina Hall Protozoology 218 (1953). 

 In this order, the central capsule is of isobilateral symmetry, having a rather 

 small main opening (astropyle) at one end and two smaller openings (parapyles) 

 at the other. The openings are located on projections of the central capsule mem- 

 brane; inside of each, the protoplasm is so differentiated as to appear to be a conical 

 bundle of fibers with the apex at the opening (in contrast to the preceding order, in 

 which the base of the conical structure is at the opening) . A mass of variously colored 

 bodies, supposedly excreted from the central capsule, lies in the extracapsular cyto- 

 plasm about the astroplyle. The skeletons consist in part of organic matter and are 

 not well preserved as fossils. 



Borgert (1896, 1900) described nuclear division in Aulacantha. A very large 

 number of chromosomes, a matter of several hundred, form a plate which splits into 

 two; the two plates move apart in a body of differentiated cytoplasm, but no definite 

 spindle, and no centrosomes, were seen. The margins of the plates draw apart faster 

 than the middles, with the effect that the plates become saucer-shaped, then bowl- 

 shaped, and finally globular, after which nuclear membranes form about them. While 

 the nucleus divides, the central capsule membrane becomes constricted by longi- 

 tudinal grooves so placed that each daughter central capsule membrane receives 

 one parapyle and an astropyle formed from half of the original astropyle. The rudi- 

 ments of additional parapyles are first seen as granules in the intracapsular cyto- 

 plasm. Each granule grows slightly and becomes "hat-shaped," and migrates so as 

 to come into contact with the central capsule membrane at the point appropriate for 

 the development of its second parapyle. 



Later, Borgert (1909) described a process in which the nucleus divides repeatedly, 

 producing many. The divisions are mitotic, with small numbers of chromosomes, 

 perhaps twenty; the eventual products become the nuclei of gametes. There are re- 

 ports, in part illustrated with photographs, of similar processes in family Thalassi- 

 collida (Hacker, 1907; Huth, 1913). According to Hollande (in Grasse, 1953) the 

 small nuclei are those of a parasitic dinoflagellate, Solenodinium. Le Calvez (1935) 

 found Coelodendrurn to produce zoospores with a pair of unequal simple flagella. 

 They resemble cells of Cryptomonas or of Bodo. 



Haeckel's legion Phaeodaria was of fifteen families. These have been maintained 

 by the generality of authors. 



A. Skeleton none or of distinct spicules; cells usually nearly spherical. 

 Family Aulacanthida [Aulacanthidae] Haeckel (1879). Aulacantha. 



Family Astracanthida [Astracanthidae] Hacker. Spicules more or less thorny at 

 the distal ends. Aulactinium. 



B. Skeleton spherical or of two concentric spheres, with no main opening. 

 Family Aulosphaerida Haeckel (1862). Aulosphaera. 



Family Cannosphaerida [Cannosphaeridae] Haeckel (1879). Cromodromys. 

 Family Sagosphaerida Haeckel (1887). 



C. Skeleton with a distinct main opening, either nearly spherical, radially sym- 

 metrical, or distinctly dorsiventral. 



