No.4175.] NWORTH-AMERICAN INVERTEBRATES. 729 
Order 5. Ploima. Not fixed ; swimming with the ciliary wreath; not 
creeping like a leech. Jaws never ramate. 
Suborder 1. Illoricata. Cuticula flexible, not hardened to form a shell 
or Zorica. 
Family 7. Microcodontide. 
Genera. Microcodon, Microcodides. 
Family 8. Asplanchnade. 
Genera. Asplanchna, Asplanchnopus, Ascomorpha, (Hertwigia ?). 
Family 9. Synchetadze 
Genera. Syncheta, (Anartani, (Polyarthra). 
Family 10. Triarthradæ. 
Genera. Triarthra, Pedetes, Pteroessa, (Polyarthra and Anarthra). 
Family 11. Hydatinadæ. 
Genera. Hydatina, Rhinops, Notops, Triphylus, Cyrtonia. 
Family 12. Notommatadæ 
Genera. Albertia, Taphrocampa, Pleurotrocha, Notommata, Copeus, 
gray Furcularia, Triophthalmus, Eosphora, Diglena, Dis- 
a, Notostemma, Arthroglena, (Drilophaga) (Monommata ?). 
Shri 2 gibus Cuticula stiffened to form a distinct armor or lorica. 
Family 13. Rattulide. 
Genera. Rattulus, Mastigocerca, Elosa, (Ccelopus?), (Diurella ?), 
Genera. MN Polychatus, Scaridium, (Stephanops). 
Family 15. Salpina 
Genera. Salpina, Diglax Diaschiza, Diplois. 
i idx 
Genera. Cathypna, Dis Monostyla. 
Family 18. Coluride. . 
Genera. Colurus, Metopidia, Monura, Mytilia, Cochleare, (Steph- 
anops). 
Family rg.  Pterodinadz. 
Genera. Pterodina, Pompholyx. 
Family 20. Brachionide 
Genera, Brachionus, Scblebci Noteus. 
ureade. 
Genera. Anurza, Notholca, Eretmia. 
Family 22. Plæsomadæ. 
Family 24. Ana apodide. . 
Genera. Anapus, (Hertwigia). 
