466 HE. B, T, BBOWNE ON [Mar. 17, 



medusa. By this it may be distinguished from another uni-tenta- 

 cular medusa — Eivphysa aurata. 



The aboral end of the umbrella varies in shape. In some speci- 

 mens it is round, and the process is conspicuous by its spine-like 

 appearance ; in others there is a gradual slope from the side of the 

 umbrella to the apex of the umbrella, forming a cone-shaped 

 summit. The manubrium is about two-thirds the length of the 

 umbrella-cavity; occasionally, when fully expanded, it may reach 

 a little -way beyond the margin. The mouth is round, without 

 lips. The stomach is attached to a short peduncle. From the 

 base of the stomach an apical stalk is always present and runs up 

 into the spine-like process of the umbrella. On the margin of the 

 umbrella there is only one large perradial tentacle, ringed with 

 nematocysts, and when fully expanded is about four times the 

 length of the umbrella. Three other perradial bulbs, long and 

 narrow, without tentacles, curl over the margin of the umbrella. 



The colour of the medusa shows little variation : the tentacle, 

 bulbs, and stomach are usually of a light pinkish colour, but some- 

 times reddish brown. In some of the largest specimens the 

 extreme apex of the spine-like process may be slightly tinged with 

 a pinkish colour. The size of the umbrella varies according to 

 age ; the youngest specimens taken in the net measured about 

 1 mm. in length, the umbrella of the largest measured C mm. 

 Many were taken about 5 mm. in length and 3 mm. in width. 



DiSTiiiuui'iON. Norway, ySars (II). Ileligoland, IlaHlauh (II, M) ; 

 Haeckel (M). 



Scotland — Orkney Islands, Forbes Sj- Goodsir (H). Shetland 

 Islands, Allman (H) ; Forbes (M). St. Andrews, Crawford (M). 

 Firth of Forth, Allman (H, M). 



England — Seaham Harbour, Hodge (II). Plymouth, Heape (II) ; 

 Allen (H, M); Garstang (M). Fowey, Alder (IT); PeacJi (M). 

 Penzance, Forbes (M). Mersey Estuary, Ilincks (II). Isle of Man, 

 Alder (II) ; Browne (M). 



Ireland — Kingstown, Haddon (H, M). Valencia Island, E, T. B. 

 (M). 



Fam. HTBOOGDONIDiE. 



Hybocodon peolifeb, Agassiz. 

 Hydroid Form. 



Bybocodon prolifer, Agassiz * {'[862) ; Allman* (1872). 



Corymorpha prollfer, Haeckel (1879) [Medusa =-f/</6ocodon 

 prolifer']. 



Medusoid Form. 



Hybocodon prolifer, Bohm (1878) ; Crawford (1895). 



Coryne {Corymorphd) fritillaria, Steenstrup (1842). 



Diplonema islandica, Greene (1857). 



Steenstrupia oivenii, Greene (1857). 



Steenstrujna globosa, Sara, M. (1859); Sars (1877). 



AmpMcodonfrUillaria, Haeckel (1879); Browne (1895). 



