Introduction to Ammal Morphology. 77 



sandy axis, while others are fine, homogeneous (Hircinia). 

 Auliskia has its fibres traversed by an Algoid ? Cacospongia 

 is loose in texture, with laminated, slightly elastic threads. 

 Spongelia is hard, brittle, and scarcely elastic. 



Order 3. Gummince horny, caoutchouc-like Sponges 

 composed of densely interwoven homogeneous or striated 

 fibres, or of mucous tissue imbedding stellate spicules. In 

 the basis are often cartilage-like cells (Kolliker}. Spicules 

 may be candelabriform (Corticium), or none (Gummina), or 

 there may be an outer surface of compacted fibres and stellate 

 spicules (Chondrilla). 



Order 4. Halichondriae siliceous Sponges, with no cortical 

 layer, and a small amount of Spongiolin, with no anchorate 

 nor defensive spicules. They may be massive, with cylindrical 

 needle-like spicules (HalichondriidDe) ; or rugose, with simple 

 spicules usually pointed at both ends (Reniera) ; or blunt, 

 often knobbed at the end (Suberites). Ancorina is fleshy, 

 with acicular spicules. Clionidae are mostly boring Sponges, 

 with pin-shaped spicules, perforating oyster-shells, limestone,. 

 They have often two kinds of papillag, pore-bearing, 

 small, and osculum-bearing, larger, fewer. The surface may 

 be beset with siliceous polygonal plates (Cliona), or mulberry- 

 like bodies (Thoosa). Raphiophora patera (Neptune's cup) 

 : large goblet-like Sponge, 2-4 feet in height, with 

 numerous octoradiate oscula. Raphyrus is an allied, irregular 

 form. The family Arenospongidce, including the genus 

 ngia, which forms a disc of agglutinated sand, and 

 :ig spicules in the sarcode and around the 

 oscula, may be worthy of ordinal rank. 



Order 5. Corticatce globose, tuberous or branched, with 



an outer cortex containing spictiligenms corpuscles, and an 



inner layer of Spongiolin threads and siliceous needles, often 



in radiating metimes the thin, niem- 



iphonia), or thicker, provided with siliceous 



globules only (('animus). 



"I" spicules, and an unsym- 



:ical central matt. T- thjra ifl i nb-orbicular, \\ith 



ii -u late spii ules radiating to the surface, \\itli 



sub-cut: The cortical spiculcs 



