Tnfrodudioji to Am'/nal Morphology. 6t, 



spicules, loosely connected into a capsule, from which 

 radiating spicules pass, with whorls of spines along their 

 length. The meshes of the capsule are three-angled, and 

 the double-contoured central capsule is freely movable 

 within. 



The Entolitha include eight families : — 9. Cladococcidae, 

 forming a basket of solid radiant spicules. 10, Colodendridae, 

 similar, with hollow spicules. 11. Acanthometridae, with no 

 framework round the central capsule, but twenty radiant, 

 symmetrical, acanthin spicules piercing it, either fused to- 

 gether in the middle (Astrolithinse) or with wedge-shaped 

 ends lying symmetrically beside each other (Acanthometrinse), 

 or only traversing the capsule, and not united at the centre 

 (Acanthochiasminae). The spicules are irregular in Litho- 

 lophinse ; some have no yellow cells. 12. Diploconidae, 

 capsule not basket-shaped, open at both ends, narrow in the 

 middle (dice-box shaped), with a strong-pointed spicule tra- 

 versing the central capsule. 13. Ommatidae, with a globular 

 framework bound together by radiating spicules piercing the 

 capsule. There may be one such frame and twenty rays 

 (Dorataspis), two (Haliomma), or more (Actinomma). 14. 

 Sponguridae — The ento-capsular skeleton is spongy, and to 

 this a system of radial spicules and an inner regular basket- 

 work is often added. There may be, within, one or more of 

 these lattice spheres, and an outer, irregular, sponge-like 

 skeleton (Spongosphaerinas), sometimes as many as three of 

 these spheres, as in Spongodict)aim, or there may be no inner 

 lattice sphere and irregular compartments in the outer 

 sponge mass (Spongodiscinae), or concentric inner chambers 

 and no lattice sphere (Spongocyclinae). 15. Discidse, 

 skeleton discoid or lenticular, with one or more concentric 

 trellis-spheres, including the central capsule (Coccodiscinse), 

 or with the central chamber not so included, and spiral or 

 concentric, ringed cavities in the skeleton (Discospirinae). 

 16. Lithelidce, skeleton of several discs whose compartments 

 are arranged spirally on a common axis. 



Order 2. Polycyttaria — Colonies ; several central capsules 

 in a common sarcode. This order includes two families : — 

 I St. Sphoerozoidce, having the central capsules included in a 



