70 FOSSIL MEDUSAE. 



Dr. Amnion's 1 classification of the fossil medusa? from the Jurassic is 

 as follows: 



CRASPEDOTuE Gegenbaur. (Not yet proved beyond doubt to exist fossil.) 

 ACRASPEB^E Gegenbaur. 



Order DISCOMEDUS,F Haeckel. 



1. Suborder Cannostomle Haeckel. (Not known.) 



2. Suborder Semostom^e L. Agassiz. 



Family Lithosemaidw Haeckel. (Fossil.) 



(1) Sem;eostoinites zitteli Haeckel. 

 Family Eulithotidce Haeckel. (Fossil.) 



(2) Eulithota fasciculata Haeckel. 

 Family (?) Pelagidce Gegenbaur. 



(3) Acraspedites antiquus Haeckel. 



3. Suborder Rhizostom^: Cuvier. 



Family LithorhizostomecB v. Amnion. (Fossil.) 



(4) Rbizostomites admirandus Haeckel. 



(5) Rbizostomites litliographicus Haeckel. 



Hcxarhizites insignis is only the six-rayed form of Bhizostomites 

 lithographicus. It may belong to the same family or to the 

 family of the Crambessidse (Subfamily Leptobrachidaj). 



(6) Leptobrachites trigonobrachius Haeckel. 



MEDUS.E of uncertain position. 



(7) Medusites deperditus Beyrich. 



(8) Medusites quadratus Haeckel. 



(9) Medusites bicinctus Haeckel. 



(10) Medusites staurophorus Haeckel. 



(11) Medusites circularis Haeckel. 



(12) Medusites porpitinus Haeckel. 



DESCRIPTION OF GENERA AND SPECIES. 



Suborder SEMOSTOMyE L. Agassiz. 



Family LITHOSEMiEID.E Haeckel. 



Genus SEM.EOSTOMITES Haeckel. 



Sem^eostomites zitteli Haeckel. 



PL XXXIX, fig. 1. 



Semasostomites zitteli Haeckel, 1874. Jenaische Zeitschr.,Vol. VIII, pp. 323-329, PI. XI. 

 Senuvostomites zitteli Ha-ckel, 1880. System der Medusen, p. 647. 

 Semceostomites zitteli Amnion, 1886. Abhandl. Math.-phys.Classe Konigl. bayerischen 

 Akad. Wiss., Vol. XV, p. 157. 



■Abhaiidl. Math.-phys. Classe Konigl. bayerischen Akad. Wiss., Vol. XV, 1886, pp. 157-158. 



