RHIZOPODA. 
Prot. 16 
Order II. Peripylaria. Fam. 6, ; l^Discida\ ^,Zygartida\ 
9, PylOnida ; 10, Lithelida. 
Order iii. Acantharia (= Acanthometrce^ J. Muller). Fam. 11, Acan- 
tlionida \ Diploconida\ 1^, Dorataspida ) Sphcerocapsida \ 
15, LitJiolophida. 
Order iv. Collodaria. Fam. 16, Thalassocollida\ 17, Thalasso- 
sphcerida. 
Order v. Phceodaria. Fam. 18, Phceocystida ; 19, Phceogromida ] 20, 
Phceophcerida ; 21, Phceoconchida. 
[It is to be noted that this division of the Phmodaria is entirely dif- 
ferent from that first put forth by the author. See Zool. Rec. xvi.] 
Subclass 2, Polycyttaria. 
Order vi. Symhelaria. Fam. 22, Collosplidcrida. 
Order VII. Syncollaria, Fam. 23 ; Sphcerozoida ’ 24, Collozoida. 
Genera, Species, &c., referred to. 
Radiolaria. 
Acanthometrida. Like the axial fibres of the pseudopodia of tho 
Ileliozoa, the acanthin spicules characteristic of this family are [found 
by Brandt, (19) p. 400, to be soluble in 10 to 20 per cent, solutions 
of chloride of sodium ; they are similarly soluble in 1 per cent, solution 
of carbonate of soda ; thus the substance composing them is better 
described as albumen than acanthin. The skeletons of siliceous Radio- 
laria contain an organic substance in addition to the silica. 
Sphcerozoida. Brandt’s investigations, (19) p. 391, figs., have convinced 
him that the nuclei of these Radiolaria are not always homogeneous ; at 
the commencement of spore-formation, they separate into two distinct 
substances, the one consisting of granules or filaments, and in mature spores 
of a complete network, and capable of taking a deep stain, the other only 
slightly susceptible to staining. The presence of a membrane on the 
central capsule is by no means universal ; it is wanting in young speci- 
mens of Sphcerozoum punctatum and in all specimens of Collozoum inerme 
and pelagicum in which spore-formation has not commenced ; the con- 
nection between the different central capsules of the colony is brought 
about by the gelatinous substance, j 
Rhaphidozoum acuferum^ Sphcerozoum italicum and spinulosum are united 
by Brandt, (19) p. 390, under the name Sphcerozoum acvferum. 
Sphcerozoum ovodimare — S. punctatum^ (19) p. 390, figs. 4-6, 10 & 54. 
Collozoum inerme^ (19) p. 393, figs. 11-13.| 
Cricoidea, term applied by Butschli, (21) p. 493, to a group composed 
of the Acanthodesmida, Lygocyrtida, and Cyrtida\ the Lygocyrtida 
appear to connect the other two families together. 
Acanthodesmida. The genera L^</ioc^VcMS and Stephanolithis defined by 
Butschli, (21) pp. 496 & 497, and other genera discussed. 
• Zygocyrtida^ (21) p. 501 : probably derived from species of Stephano- 
lithis wanting the secondary skeletal ring. Dictyospyris, Ceratospyris, 
Cladospyris, Petalospyris : characters revised. The species of the group 
may be associated with one or other of these four types, so as to 
1881. [voL. xviir.] D 5 
