150 THE VOYAGE OF H.M.S. CHALLENGER. 



Genus 25. Lilyopsis, 1 Chun, 1885. 

 Lilyopsis, Chun, Sitzungsb. d. k. Akad. d. Wiss. Berlin, Feb. 5, 1885, p. 18. 



Definition. — Diphyidse with two rounded, hemispherical or mitriform, edgeless 

 nectophores, of similar form and subequal size, opposed to one another. A hydrcecial 

 canal is formed by the opposite hemicylindrical ventral grooves of the two nectophores. 

 Bracts hemispherical, mitriform, or reniform. Phyllocyst with (four) radial canals. Each 

 cormidium with a sterile special nectophore. 



The genus Lilyopsis was founded by Chun in 1885 (86) for those Diphyidae, formerly 

 described as Prayw, which differ from the true Prayse in two important points. The 

 Eudoxiae of Praya are composed of two persons, a sterde medusome (bract with siphon 

 and tentacle), and a fertde gonophore. The Eudoxiae of Lilyopsis possess, besides, a third 

 medusome, a sterile special nectophore, and usually they have a cluster of gonophores 

 instead of a single fertile medusoid. Lilyopsis, therefore, bears the same relation to 

 Praya that Diphyopsis has to Diphyes. The special nectophore is in some species of this 

 genus more medusiform than in any other Siphonanthae. It possesses a circle of 

 numerous rudimentary tentacles at the margin of the umbrella, and, besides, often a 

 number of red pigment spots, which may be regarded as ocelli. Lilyopsis agrees in this 

 respect with the nearly allied Desmophyes (PI. XXX.). 



It is probable that in some species of Lilyopsis the cormidia are detached from the 

 stem, and represent a self-subsistent free-swimming form of Lilsea (Genus 17b). 



The first described species of Lilyopsis (1853) is the Mediterranean Praya diphyes 

 of Vogt (6, Tab. xvi., xvii.) and of Kolliker (4, Taf. ix.). Another Mediterranean species 

 was figured in 1870 by Metschnikoff under the name Praya medusa, and described 

 in the Eussian language, therefore inaccessible. It is probably the same as that of which 

 Fewkes published a figure in 1880 (42). A third species, also Mediterranean, was 

 announced by Chun in 1885 under the name Lilyopsis rosea.' 2, A fourth species, Lily- 

 opsis catena, similar to the latter, was observed by me in 1866 in the Canary Island 

 Lanzerote, but not sufficiently examined. 



Subfamily Diphyopsid^:. 



Genus 26. Galeolaria, 3 Lesueur, 1807. 



Galeolaria, Blainville, Manuel dActinologie, 1834, p. 139. 



Definition. — Diphyidae with two angular slenderly pyramidal nectophores of similar 



form and subequal size, one placed behind the other. First nectophore without 



hydrcecium. Cormidia without special nectophores. Bracts conical or spathiform, with 



a pointed apex. Phyllocyst small or rudimentary, without radial canals. 



1 Lilyopsis = Similar to a lily. - 86, p. 18, Taf. ii. figs. 12, 13. 



3 Galeolaria = Provided with small helmets, galeola. 



