LITERATURE OF THE HYDROMEDUSAE 57 



fined to tlie lower surface of the colony, including numerous gastro- 

 zooids. 



Family 17. Stephalidae. Genera — S(q}halia, Hkl. ; fitephonalia, 

 Hkl. Family 18. Ehodamidae. Genera — Auralia, Hkl. ; Rhodalia, 

 Hkl. ; Angelopsis, Fewke.s. 



Sub-Order 5. Cystonectae. 



Definition. — Siplionophora with an apical hollow pneumatophorc, 

 without nectophores or bract.s. Ga.strozooids generally numerous, 

 arranged either on the lower side of the pneumatophore, or on a long 

 tubular coeno.sarc 



Family 19. Cystaliidae. Genu.s — Cystalia, Hkl. Family 20, Rhizo- 

 PHYSIDAE. Genera — Aurophysa, Hkl.; Cannophysa, Hkl.; Linophysu, 

 Hkl. ; Nectoplujsa, Hkl. ; Fneumophysa, Hkl. ; Rhi>:opkysa, Per. Le.s. ; 

 Pterophysa, Studer ; Pleuropkyaa, Fewkes. Family 21. Salaciidae. 

 Genus — Salacia, Hkl. Family 22. Epibulidae. Genera — Epibulia, E.sch. ; 

 Angela, Less. Family 23. Phy.saliidae. Genera — Alophoia, Brandt ; 

 Arethusa, Hkl. ; Fhysalia, Lamk. ; Caravella, HkL 



Incertae sedis. 



(Hydromedusae which are not referable to any known order of the 

 group.) 



Limnocodium, Allm. ; Limnocnida, Giinth. ; Protohydra, Greef ; 

 Microhydra, Potts ; Tetraplatia, Busch. 



LlTEllATUKE OK HyDUOMEDUSAE. 



As far as possible only one paper on each special subject has been cited, in 

 whieli the student will find references to the earlier literature. 



The general subject : — 



1. Allman. Monograph of the Gymnoblastic or Tubulariau Hydroids, 1871-72. 



2. Allman. Chall. Rep. Zool. vii. (Hydroidea, pt. i.) ; xxiii. (Hydroidea, 



pt. ii.). 



3. Cfum. Bronn's Klasseu und Ordnuiigen des Thierreichs. Coelenterata, 



1889 (in progress). 



4. Ifaeckel. System der Medusen, 1879-80. 



5. Haeckcl. Chall. Rep. Zool. iv., Deej) Sea Medusae, 1882. 



6. Hertwi;/. Organismus der Medusen. Denkschr. Gesell. Jena, ii. 1878. 



7. Hincks. British Hydroid Zoopliytes, 1868. 



8. Jackson. Forms of Animal Life, pp. 745-780, 1888. 



9. Lankester. Encyclopaedia Britannica, ed. ix., article "Hydrozoa," 1881. 



10. Weismann. Enstehung der Sexualzellen bei den Hydromedusen, 1883. 



Embryology : — 



11. Balfour. Treatise on Comparative Embryology, 1880-81, 



12. Korschelt a.n(\ Heuler. Text-book of tlie Emltryology of Invertebrates. Eug. 



trans., 1895-99. 



13. Mctschnikoff. Emljryologische Studien an Medusen, 1886. 



18 



