CLASSIFICATION OF CRINOIDS. 115 
Division II.—Fisrunata (= Tesselata, pars). 
Arm-plates with dorsal canal; calyx-plates imperforate. The latter comparatively 
large, in few zones. Known genera exclusively Paleozoic. 
1. Ramosa:—Arms long, many-branched, dorsally canaliferous, without pinnulæ. 
Basals (normally) in two zones, 5, 5, or 3, 5. 
Fam. 18. Cyathocrinide (Typ. gen. Cyathocrinus, Up. Sil. to Permian ; Zuspirocrinus, Botry- 
ocrinus, Ophiocrinus, Sicyocrinus, Up. Sil.; Carabocrinus, Palæocrinus, Ly. Sil.; Barycrinus, Carb.). 
Fam. 19. Taxocrinidæ (Typ. gen. Taxocrinus, Forbesiocrinus, Up. Sil. to Carb.; Myelodac- 
tylus, Nil; Gissocrinus (?), Up. Sil.; Leeythocrinus, Dey.). 
§ 2. Foliata :—Arms more or less united : typically, foliaceous or broadly retiform, with 
large dorsal canal. Basals in two zones, 5, 5. Stem, thick, with lateral pores, 
Family 20. Crotalocrinide (Typ. gen. Crotalocrinus, Enallocrinus, both, Up. Sil.). 
§ 3. Fimbriata:—Arms simple, very broad, with short (often incurved) pinnulæ or 
accessory plates on inner side; dorsally, a well marked canal. Calyx broad and low, made 
up of a few large plates. Stem tetramerous, or circular. 
Fam. 21. Cupressocrinide (Typ. gen. Cupressocrinus, Dev; Symbathocrinus, Dey. Carb.; 
Edriocrinus (2), stemless, Up. Sil., Dev.). 
$ 4. Quadrata :—Stem essentially tetramerous ; calyx small, made up of a few compara- 
tively large plates: upper basals, 5. Arms simple, or slightly divided, with dorsal canal, 
Fam. 22. Gasterocomide (Typ. gen. Gasterocoma, Dex; Myrtillocrinus, Dev; Nanocrinus. 
Dey.). 
Drviston IIT.—CANALICULATA (= Articulata). 
Calyx-plates traversed from the basals, upwards, by delicate, ridiating canals, and * 
interpenetrating more or less distinctly at their upper and lower edges. Arm-plates, also, 
dorsally canaliferous. Genera, Post-Paleeozoic : extinct and living. 
GROUP 1.—CRASSICINCTA : 
Body-plates of uniform, normally thick texture. 
§ 1. Frondosa : —Arms many-branched and thickly pinnulated, 1-plated. Calyx, shal- 
low. Stem essentially pentagonal, with attached cirrhi. 
Fam. 23, Pentacrinide (Typ. genus, Pentacrinus [including Extracrinus, Cainocrinus, etc.], 
Triassic to Existing Period). 
§ 2. Vagata :—Calyx in adult condition detached from the stem. Arms simple, 1- 
plated, numerous. 
Fam. 24. Comatulide (Typ. gen. Antedon or Comatula, Comaster ; both, Jurassic to Existing 
Period ; Actinometra, Recent). 
§ 3. Florifera:—Calyx broad and shallow; basals and lower basals, each 5. Arms, 
2-plated, 1-plated, simple, in more or less close contact. Stem-plates round, mostly alter- 
nating in diameter. 
Fam. 25. Encrinide (Typ. genus Encrinus, Triassic). 
§ 4. Coadunata:—Calyx small, pentagonal, composed of few plates. Arms short and 
thick; 1-plated. Stem short, round, made up of a few long segments. 
Fam. 26. Eugeniacrinide (Typ. gen. Eugeniacrinus, Phyllocrinus, Jurassic, Ly. Cretaceous). 
§ 5. Conformata :—Calyx, typically, pyriform, merging gradually into the stem: the 
