REPORT ON THE EADIOLARIA. 



895 



We divide tlie immense legion of Nassellaeia into two large orders, the 

 Plectellaria without complete lattice-shell, and the Cyrtellaria with a 

 complete lattice-shell or a "cephalis," including the central capsule; the latter, of 

 course, have arisen from the former. The Plectellaria comprise three different 

 suborders, the Nassoidea (without skeleton), the Plectoidea (with a tripodal 

 skeleton, -ndthout ring), and the Stephoidea (with a primary sagittal ring, with or 

 without tripod). The Cyrtellaria again also comprise three different suborders, the 

 Spyroidea (with bilocular cephalis and a sagittal constriction), the Botryodea 

 (with multilocular and lobate cephalis, exhibiting two or more constrictions and three 

 or more lobes), and the C y r t o i d e a (with simj)le, unilocular cephalis, without con- 

 striction). 



I. Order 



PLECTELLARIA. 



Nassollaria without complete lattice-shell. 



Synopsis of the Orders and Suborders of Nassellaria. 



' No skeleton, . . . .L Nassoidea. 



Skeleton with a basal tripod, without 



IL Order 



CYRTELLARIA. 



NasseUaria with a complete lattice-shell. 



2. Plectoidea. 



Skeleton with a sagittal ring (usually 



without tripod), . . . 3. Stephoidea. 



Cephalis bilocular, with a sagittal con- 

 striction, . . . . 4. Spyroidea. 



Cephalis multilocular, with two or more 



constrictions and lobes, . . 5. Botryodea. 



Cephalis simple, without constriction and 

 lobes, . . . . . 6. Cyrtoidea. 



Order V. PLECTELLAEIA, Haeckel, 1883. 



Definition. — Nassellaeia without complete lattice-shell, usually with an incomplete 

 skeleton, formed of a ring, a tripod, or an irregular framework. 



Suborder I. NASSOIDEA, Haeckel. 

 Definition. — Nassellaeia without skeleton. Single family Nassellida. 



