32 ARTHROPODA-ECHINODERMATA 



Order NYMPHONOMORPHA 



Nytnphon 

 Order ASCORHYNCHOMORPHA 



Ascorhynchus 

 Order PYCNOGONOMORPHA 



Pycnogonum 



Class PENTASTOMTOA 



Order CEPHALOBAENTOA 



Cephalobaena; Reighardia 

 Order POROCEPHALroA 



Sebekia; Lingua tula 

 Class TARDIGRADA (water-bears) 



Order HETEROTARDIGRADA 



Echiniscus; Tetrakentron 

 Order EUTARDIGRADA 



Macrobiotus ; Hypsibius; Milnesium 



Phylum CHAETOGNATHA (arrow worms) 



Sagitta; Spadella; Eukrohnia; Ptewsagitta; 

 Heterokrohnia 



Phylum POGONOPHORA ( = Brachiata) (beard worms) 



Order ATHECANEPHRIA 



Oligobrachia; Siboglinum 

 Order THECANEPHRIA 



Heptabrachia ; Zenkevitchiana; Lamellisabella; 

 Spirobrachia 



Phylum ECfflNODERMATA 



Sub-phylum PELMATOZOA 



Class CRINOIDEA 



Order ARTICULATA^ 



Antedon, Tropiometra (feather stars) ; Rhizocrinus, 

 Metacrinus (sea lilies) 

 Sub-phylum ELEUTHEROZOA 



Class HOLOTHUROIDEA (sea cucumbers) 



Order ASPIDOCfflROTA 



Holothuria; Stichopus; Mesothuria 

 Order ELASIPODA 



Deima; Kolga; Elpidia; Pelagothuria 



^ See Brachiopoda, p. 21. 



