REPORT ON THE RADIOLARIA. 



1133 



the majority, however, of Cyrtoidea, the capsule develops on its basal face a number 

 of depending lobes, as were also found in some Spyroidea (and probably also 

 B o t r y o d e a). In this respect we may distinguish two main forms of the capsule in the 

 Cyrtellaria, viz., the primary simple, not lobate form, and the secondary lobate form. 

 The central capsule is originally always enclosed in the cephalis, and has there a simple, 

 subspherical, ellipsoidal or ovate form. As soon as their growth increases, and the enclosing 

 cephalis becomes too narrow, it sends out prolongations in the form of basal lobes, which 

 depend from its base, and proceed through the pores of the basal lattice of the cephalis, or 

 the cortinar pores. In the great majority of Cyrtoidea in which the capsule was 

 observed, either three or four such lobes were seen (already described by J. Miiller). Of 

 course this number depends upon the number of cortinar pores, which is either three or 

 four ; therefore in the Cyrtoidea with three pores in the cortinar plate, we find three 

 lobes of the central capsule (an odd posterior and two paired anterior) ; in the 

 Cyrtoidea, however, with four pores in the cortinar plate (the majority) we find four 

 lobes of the central capsule (two smaller anterior jugular and two larger posterior cardinal 

 lobes). Usually each lobe is ovate or pear-shaped and encloses a large oil-globule, and 

 often also an apophysis of the cell-nucleus. 



Section I. MONOCYETIDA, Haeckel, 1862, Monogr. d. Radiol, pp. 280, 281. 



Definition. Cyrtoidea monothalamia, with simple, not jointed shell (or cephalis), 

 without transverse constrictions. 



Family LIX. 



Tripocalpida. 

 Three radial apophyses. 



Synopsis of the three Families and six Subfamilies of Monocyrtida. 



| Mouth open, . .1. Archipilida. 



j Mouth closed, . . . . .2. Archiperida. 



| Mouth open, . . 3. Archiphormida. 



Family LX. 



Phaenocalpida. 



Numerous radial apophyses. 



Family LXI. 



Cyrtocalpida. 

 No radial apophyses. 



) Mouth closed, . 

 \ Mouth open, 

 ) Mouth closed, 



4. Archiphaenida. 



5. Archicorida. 



6. Archicapsida. 



Family LIX. TRIPOCALPIDA, n. fam. 



Archipilida et Archiperiila, Haeckel, 1881, Prodromus, pp. 427, 429. 



Definition. Monocyrtida triradiata. (Cyrtoidea with a simple, not jointed shell, 

 representing a simple cephalis, with three radial apophyses.) 



