1879.] PROF. J. R. GREENE ON A RARE MEDUSA. 797 



We may now trace the attempts of successive zoologists to inter- 

 pret Charybdeidce. Linnaeus records the species of Plancus in the 

 bystema Naturae (ed. xii. p. 1097) 1 as Medusa marsupialis. He is 

 followed by Gmehn 2 and Modeer 3 . 



In 1809 Peron and Lesueur found the genus Carybdea. It in- 

 cludes their new spec.es {C.periphylla) together with that of Plancus 

 Lamarck* Cuvier 5 , Goldfuss", Schweigger', the editors of the Ency- 

 clopedic Methodique 8 and Latreille 9 , accept the new genus 



Eschscholtz does not cite Pe'ron's new species or genus He refers 

 the species of Plancus to Oceania as O. marsupialis 10 



Milne-Edwards suggests the affinity of C. marsupialis to C. alata 

 Itevnaud, and Bursarius cytherece, Lesson 



De Blahmlle" retains the genus of Peron, and gives in his Atlas 

 the first copy of Lesueur s previously unpublished figure of C. peri- 

 phylla. Coloured figures of this species (likewise copied from 

 Lesueur s drawing) and of C. marsupialis (original) are added b V 

 Milne-Edwards to the large illustrated edition of 'Le Regne Animal*' 

 _ Lesson -is the first to break up the genus of Peron. His Carybdea 

 includes C perrphylla, while the species of Plancus is referred (as 

 M. planci) to the new genus Marsupialis. This procedure is sub- 

 secpuently sanctioned by Agassiz. Lesson proposes the two tribes of 



aZ^m K ° mbl °P a ^ h X™ ie * wi ] h ve '-y P e C"liar genitalia. Each of these 

 Ices not as m other Charybde.d*, form a continuous lamina freely projecting 

 mto its Lateral pouch. The gemtalia are constituted rather by the modified 

 walls of diverticula from the pouches. They form, when mature, branched 

 arbuscules reaching far mto the interior of the disk itself and splinted bv 

 processes of its gelatinous substance. In the lumen between these processes and 

 their investing inner membrane [endoderm] the sexual products are developed 

 Semper further notes a small acaleph, likewise veiate and probablv charvb- 

 deoid with very complex marginal bodies. In this connexion he declares it 

 unnatural to insist on establishing two primary groups of discoid Medusa after 

 the manner of Eschscholtz and his successors. Such divisions, based on single 

 characters, arise from the delusive desire to thrust a straight-jacket of man's 

 device upon the free creations of nature (Eeisebericht, 1864) 



* Tom. i. pars ii. (1767). Also ed. x. torn. i. p. 660 (1760). 



2 Syst. Nat. p. 3154. ' 



3 Whose work I have not seen. I take this reference from Eschscholtz. 



* .Hist. nat. des animaux sans vertebres, tome ii. p 496 (1816) 



* Le Eegne animal, tome iv. p. 59. " Lorsque ces animaux si simples prennent 

 plus de concavite , leur surface inferieure devient interieure, et pent etre reeardee 

 comme un veritable estomac. Ce sont les Carybdees, Per. Ceux oil Ton ne 

 voit a lmteneur aucunes traces de vaisseaux, ne different proprenient des hudres 

 que par la grandeur. 1817. " 



* Handbuch der Zoologie, erste Abtheilung, p. Ill (1820). 



7 f mno b ,m h der Natul -geschichte der skelettlosen ungegliederten Thiere, 



p. Q\)\J (lo-iU). 



s Histoire naturelle des Zoophytes ou Animaux Eayonnes, faisant suite a 

 1 Histoire naturelle des Vers de Bruguiere ; par MM. Lamouroux, Bory de Saint- 

 Vincent et Eud. Deslongchamps, tome ii. p. 165 (1824). 



9 Families naturelles du regne animal, p. 540 (1825) 



» System der Acalephen, p. 101 (1829). De Blainville carelessly states that 

 Jischscholtz places this species in Mqiiorca. 



V2 ^™ wl d'Actinologie, p. 275, and Atlas, pi. xxxi. f. 1 (1834). 



Prodrome (1837) ; Histoire naturelle des Zoophytes— Acalephes (1843). 



