OCR Text |
Show 1886.] POSITION AND CLASSIFICATION OF SPONGES. 591 16. i 18. 'With lithistid irregular tetraxon spicules With tetraxon spicules of irregular shape; askeletous forms with large cbambers, which have large outlets With monaxon tylostylote spicules Without supporting spicules; flesh-spicules when present polyact, with small chambers which have narrow outlets Spicules quite irregular 18. Spicules rod-shaped, with terminal tufts of branches 19. _ Spicules tetractin, with terminal branches 20. 18. (19.) (20.) (21.) Ehizomorinidce. Anomocladinidoe. Tetracladinidw. (19.) 22. 24. 'The spicules are chiefly tetracts with equal rays and candelabras 22. There are large tetract spicules with three equal rays lying tangentially in or beyond the surface, and one differentiated, radial ray ... (23.) With small inconspicuous ciliated cbambers with small outlets 24. With large conspicuous ciliated cbambers with wide outlets / With candelabra 21. \ With simple tetracts 22. (25.) Corticidce. Pachastrellidce. ,~-* | W i t h scattered tetracts, triacts, diacts 23. Plakinidce. { ' \ Without spicules 24. Oscarellidce. (23.) 26. [ 28. f Tetracts with differentiated large centripetal ray and large tangential rays numerous 26. Tetracts with differentiated large centripetal ray rare, with small tangential rays (27.) With spherasters 25. Geodidce. Without spherasters 28. Flesh-spicules euaster and oxyaster 26. Stellettidce. Flesh-spicules spirastrella 27. Theneidce. Flesh-spicules spirula and sigmata 28. Tetillidce. (27.) Without flesh-spicules 29. Tethyopsillidw. (20.) •< I The widened distal ends of the radial spicule-bundles divide tbe regular subdermal cavities into ectochona? or vestibules at tbe entrance of tbe inhalant canals 30. Between tbe distal ends of tbe radial spicule-bundles ecto- and entochonae are found 31. The inhalant pores lead direct into tbe inhalant canals 29. With spirastrellid flesh-spicules 32. With sigmate flesh-spicules 33. Without flesh-spicules 34. Tethydce. Sollasellidce. 29. Spirastrellidm. Suberamatidm. Suberitidce. 91 . J" W i t h polyact flesh-spicules 35. Chondrillidee, v**-''\ Without flesh-spicules 36. Chondrosidce. |