I02 MEDUSA. I. 



Genus Eirene Eschscholtz. 



Eirene viridula (Peron et Lesueur). 



Maver 1910, Medusse of the World, p. 311. 



Umbrella vers- flat, about 6— 15 mm wide; gelatinous substance thin. Stomachal peduncle half as long as bell-radius, 

 pyramidal, slender. Stomach small, with 4 long, crenulated hps. 4 radial canals, very narrow. Gonads Hnear, somewhat sinuous, 

 developed along the subumbrella parts of the radial canals. 50—60 short tentacles and about 100 even smaller tentacles; each 

 of the latter is flanked by a pair of cirri; each of the tentacular bulbs bears an abaxial e.xcretion papilla. There are about 100 

 small marginal vesicles, each containing 24 concretions. Velum very narrow. Stomach, gonads, and tentacles milky-white, 

 green or reddish. 



Atlantic coasts of Europe, Mediterranean. 



Genus Tima Eschscholz. 



Tinna bairdii (Johnston) Forbes. 



Plate \', figs. 4, 5, 6, 7, S, 9, 10. 



Dian<ra Bairdii Johnston 1833. Illustrations in British Zoology. Art. IV. — Mag. Nat. Hist. \'ol. 6. — 



p. 320, fig. 41. 

 — — Thompson 1844. Report on the Fauna of Ireland, Tn\-ertebrata. — Rep. 13th Meeting, 



Brit. Assoc. — p. 282. 

 Tima? — Forbes 1846. On the Puhnograde Meduste of the British vSeas. — Ann. Mag. Nat. Hist. 



Vol. 1 8. — p. 286. 

 Medusa [TiiiKi Eschsch.) Dalyell 1847—48. Rare and remarkable Animals of Scotland. \'ol. 2. — P- 250; 



1^1- 52, fig- 5- 

 Tinm Bairdii Forbes 1848. British Naked-eyed Mednste. — p. 37; PI. 5, fig. i. 



— — Allman 1S71. Monograph of the Gymnoblastic or Tubularian Hydroids. — pp. 36, 140, 



figs. II, 12. 



— — Bohm 1878. Helgolander Leptomedusen. — Jenaische Zeitschr. Bd. XII (N. I*'. \'ol. I). — 



PP- 143. 145- 



— — Haeckel 1879. System der Medusen. — p. 205. 



Description: 



Umbrella hemispherical or somewhat higher than a hemisphere, about 60 mm wide when fully 

 developed. Gelatinous substance ver\- thick. The stomachal peduncle is nearly conical; it is highly 

 contractile; its length as well as the width of its base are, accordingh', \er\- much \ariable, and mea- 

 surements of preserved material are, therefore, of no great value; but the approximate dimensions may 

 be stated as follows: The diameter of the base of the peduncle varies between about ' , and ^ 5 of the 

 diameter of the bell; the length i.s, when expanded, about equal to the bell-diameter, the peduncle 

 extending more or less beyond the level of the bell-margin. 



The stomach (Plate V, fig. 5) is small, .square, fixed to the flattened terminal end of the pe- 

 duncle by a cross-shaped figure; thus there are four flat, triangular pouches between the dorsal wall 

 of the stomach and the terminal end of the [leduncle. In some cases, i. e. in certain conditions of con- 

 traction, the entire stomach is cross-shaped in trans\erse section. The four perradial lines of attachment 



