230 Introduction to Animal Morphology. 



firmly rooted, jointed (Catenicellidse, Salicornaridae, &c.), or 

 unjointed, flexible, never attached for its whole length 

 (Scrupariadae, Flustridse, Gemellaridae, &c.), orincrusting, ad- 

 herent directly to foreign bodies (Escharidse, Hippothoidae, 

 Porellidse, &c.) 



Sub-order 4. Paludicellida — freshwater, horny; tentacle 

 sheath not fully protrusible ; cells spindle-like ; mouth tubu- 

 lar; common stem none, includes one genus, Paludicella. 



Sub-order 5. Urnatellida — one freshwater soft form, 

 whose personas are incompletely retractile into the semicir- 

 cular cell ; stalk jointed, slightly branched. 



Sub-order 6. Loxosomida — a marine polypoid passage 

 form with a pillar and foot ; ten tentacles ; no anus, and 

 lateral gemmation. 



Order 2. Phylactolcemata {Albnan) — lophophore horse- 

 shoe-shaped, with many tentacles, and an epistome ; cells 

 equal, without polymorphism ; never calcareous ; reproducing 

 often by statoblasts (in the third sub-order only). This in- 

 cludes three sub-orders : — 



Sub-order i. Rhabdopleurida — marine, abyssal, with 

 branched, adherent, membranous stock imbedding a chitinous 

 rod, to which the polypides are attached by processes or 

 funiculi. The bilateral lophophore has a large shield-like 

 organ on its haemal side, made of the two coalescent lateral 

 embryonic lobes. 



Sub-order 2. Pedicellineae — one marine genus ; cells soft, 

 hemispherical, stalked, springing irregularly from a common 

 stolon ; tentacles solid, partly retractile, united at base into a 

 calyx. 



Sub-order 3. Lophopoda — freshwater, horny ; the arms of 

 the lophophore free or obsolete ; cells cylindrical, dichoto- 

 mously branched : tentacles fully retractile ; colony with no 

 special stem. These may have an adherent stock and stato- 

 blasts unarmed with hooks^' (Plumatellidse), or a discoidal 

 colony and two circlets of hooks on the statoblasts (Cristatel- 

 lids). 



* Except in Pectinatella. 



