HELIOZOA KADIOLARIA 



77 



SpL'MELLARIA. 



Sublegion (1). Colloparia.'^ — Skeleton absent or of detached spicules; 

 colonial or simple. 

 Order i. Colloidea.- — Skeleton absent. (Families 1, 2.) ThalassicoUa 

 Huxl. ; Thalassoj^hysa Haeck. ; Collo:.omn Haeck. ; Collo.sphaera 

 J. Miill. ; Actissa Haeck. 

 Order ii. Beloidea. — Skeleton spicular. (Families 3, 4.) 

 Sublegion (2). Sphaerellaria. — Skeleton continuous, latticed or spongy, 

 reticulate. 



cent, caps 



Fig. 12,.—Aciinomma asteracanthion. A, the shell with portions of the two outer 

 spheres broken away ; B, section sliowing the relations of the skeleton to the 

 animal. cent, caps, Central capsule ; ex. caps.pr, extra-capsular protoplasm : nn, 

 nucleus ; sk. 1, outer, .■<k. 2, middle, sk. 3, inner sphere of skeleton. (From Parker 

 and Haswell, after Haeckel and Hertwig.) 



Order iii. Sphaeroidea. — Skeleton of one or several concentric 

 spherical shells; sometimes colonial. (Families 5-10.) Haliomma 

 Ehrb. ; Actinomma Haeck. (Fig. 23). 



Order iv. Prunoidea. — Skeleton a piolate sjihaeroid or cylinder, 

 sometimes constricted towards the middle, single or concentric. 

 (Families 11-17.) 



Order v. Discoidea. — Shell flattened, of circular plan, simj^le or con- 

 centric, rarely spiral. (Families 18-23.) 



Order vi. Larcoidea. — Shell ellipsoidal, with all three axes unequal 

 or irregular, sometimes becoming spiral. (Families 24-32.)- 



1 K. Brandt, in Arc.'i. Prot. i. 1902, p. 59, regards the presence of spicules as not 

 even of generic moment, and subdivides the Collodaria into two families — Ct)//w^(6 

 (solitary), and Sphaerozoea, colonial, i.e. with numerous central capsules. 



- Drover adds an additional order— S]iiiaeroin-lida, distinguished by a basal (or 

 .1 basal and an apical i jiylonie. 



