COliONAT.K — nOUICOLPA. 54 1 



Order CORONATE Vanhbffen, 1892. 



ni!com<:du!<v (in part), Hacckel, iS6f), Gcncrelli- Morphologic, Bd. 2, p. 60; 1880, Syst. dt-r Medusen, p. +50. 



Coronal.c, Vanhoffen, 1891, Ergcb. dcr Plankton f;xped., Bd. I, K. c, p. 21; 1902, Wisscn. Ergcb. dcutsch. Tiefsce Expel., 



Dampfer I'aUivia, Bd. 3, Lief. I, p. 51; 1906, Nordischcs Plankton, Acraspcde Mcdusc-n, Nr. 11, p. 41. 

 Coronala, Maas, 1903, Scyphomedusen der Siboga Expedition, Monog. 11, p. 5; 1907, Ergeb. l-'ortschritte dcr Zool., Bd. 1, pp. 191, 



199. — BiGELOw, H. B., 1909, Mem. Mus. Conip. Zool, at Harvard College, vol. 37, p. 20. 



CHARACTERS OF THE CORONATE. 



Scyphomedusx \vi:li marginal tentacles, a single central mouth-opening, and with the 

 bell-margin cleft into lappets. The rhopalia arise from clefts between these lappets, and 

 their entodermal cores contain a terminal mass of crystalline concretions of entodermal origin. 

 Ocelli may or may not be present. The medusae are free-swimming and have no aboral 

 stalk for attachment. 



With a circular, or coronal, furrow in the exumbrella, and peripheral to this there is a zone 

 of gelatinous thickenings in the radii of the tentacles and sense-organs. These thickenings, 

 or pedalia, are divided one from another by radiating clefts which alternate in position with 

 the marginal sense-organs and the tentacles, and are in the middle (axial) lines of the marginal 

 lappets. These marginal lappets project beyond the zone of the pedalia. The tentacles are 

 solid, or not hollow, throughout their lengths. The throat-tube is simple, short, and provided 

 with simple lips, without curtain-like appendages. 



The families of the Coronatae are as follows: 



PeriphyllidcE Cr.AUS, 1886. 4 interradial rhopalia and 4 or more tentacles. 



ParaphylliniJcE Maas, 1903. 4 perradial rhopalia and 4 or more tentacles. 



Ephyropsid^e Claus, 1883. 8 rhopalia (4 perradial and 4 interradial) and 8 or more tentacles. 



CoIlaspidiV Haeckel, 18S0. Numerous rhopalia, alternating with an equal number of tentacles. 



AtorellJd.e Vanhoffen, 1902. With 6 rhopalia and 6 tentacles. 



Family PERIPHYLLIDiE sensu Claus, 1886. 



Peromeduscs (in part), Haeckel, 1880, Syst. der Medusen, p. 396. 



Periphyllidir, Clavs, 1886, Class, der Medusen, Arbeit. Zool. Inst. Univ. Wien, Bd. 7, pp. 97-1 10. — Vanhoffen, 1892, Akalephen 



der Plankton Expedition, Bd. 2,K.d., p. 21. — Maas, 1897, Mem. Mus. Comp.Zool. at Harvard College, vol. 23, No. I, p. 28; 



1906, Fauna .^rctica, Bd. 4, Lfg. 3, p. 501. — Vanhofffn, 1906, Nordisches Plankton, No. 11, .Acraspede Medusen, p. 41. — 



BiGELow, H. B., 1909, Mem. Mus. Comp. Zool. at Harvard College, vol. 37, p. 23. 

 Peromedusx, von Lzndenfeld, 1884, Proc. Linnean Soc. New South Wales, vol. 9, p. 166. 



FAMILY CHARACTERS. 



Coronatae with 4 interradial pedalia which bear marginal sense-clubs, and with 4, or 

 more, pedalia which bear tentacles. 



The genera of the Periphyllidae are as follows: 



Pericolpii Haeckel, 1880, sensu Vanhoffen, 1902. With 4 perradial tentacles, 8 adradial lappets, 8 gonads. 

 Periphylla Steenstrl'p, 1837. With (4 X 3) 12 tentacles, 4 perradial, 8 adradial. 16 lappets, 8 gonads. 

 Periphyllopsis Vanhoffen, 1900. With (4 X 5) 20 tentacles, 24 lappets. 

 (.') Nauphantopsis Fewkes, 1885; sensu Vanhbffen, 1902. With (4 X 7) 28 tentacles, 32 lappets. 



Genus PERICOLPA Haeckel sensu Vanhbffen. 



Pericolpa+Pericrypta, Haeckel, 1S80, Syst. der Medusen, pp. 413, 414. 640. 



Pericolpa, Vanhoffen, 1902, Wissen. Ergeb.deutsch. Tiefsee Exped., Valdivia, Bd. 3, Lfg. I, p. 50.— Maas, 1903, Scyphomedusen 

 der Siboga Exped., Monog. 11, p. 12; 1906, Die Arktischen Medusen, Fauna Arctica, Bd. 4, p. 502. 



GENERIC CHARACTERS. 



Periphyllidae with 4 interradial rhopalia, 4 perradial tentacles, 8 adradial lappets. The 

 8 gonads are adradial or on both sides of the 4 interradii. 



Haeckel's Pericrypta is doubtless only a more advanced stage in the growth oi Pericolpa. 

 The interradial taeniolae are solid in the young, but become hollowed by the development of 

 4 pits in the floor of the subumbrella, and the gastral filaments increase with age. In the 

 structure of the gastrovascular system this genus resembles Periphylla, and were it not tor 

 the probability that the number of metameres apparently does not increase in the free ephyrx 



