464 MR. E. T. BROWNE ON [Mar. 17, 



Sara* (1877); Haeckel (1879); [meinsa. = Hybocodon nutans] 

 Haddon(1885); Hincks (1886); Hartlaub (1894) ; Allen* (1895). 

 Corymorpha galanthtis, Haeckel (1879). 



Medusoid Form. 



Cor?/TOo?yAa»iMto»is, Allinan(1863); Garstang (1894); Crawford 

 (1895). 



Steenstrwpia rubra, Forbes (1848); Peach (1849); Haddon 

 (1885) ; Browne (1895). 



Steenstrupia flaveola, Forbes (1848). 



Steenstrupia galanthus, Haeckel (1879) ; Hartlaub (1894). 



The hydroid form of GorymorpJia nutans with medusa-buds was 

 first described by Sars from specimens taken on the Norwegian 

 coast. Forbes and Goodsir a few years later added the hydroid to 

 the British list by finding specimens off the Orkney Islands. 

 Hodge has described specimens from Seaham Harbour and Allman 

 from the Firth of Forth. 



Allman, Hincks, Hodge, and Johnson consider the British species 

 to be that described by Sars, and call it Corymorpha nutans. 



Haeckel, however, states that the Norwegian species is quite 

 distinct from the British species. He retains the name Cory- 

 morpha nutans for the Norwegian hydroid and calls the medusoid 

 Hybocodon nutans. The English species has been given the new 

 name of Corymorpha yalanthus and its medusoid called Steenstrupia 

 galanthus ; under the latter name Haeckel places the medusoid 

 Steenstrupia rubra, Forbes, as a synonym. 



This separation is entirely based upon the shape of the umbrella 

 of the medusa. Sars described the young medusa upon the hydroid 

 as having an oblique margin to the umbrella, like Hybocodon pro- 

 lifer. Tiiis has led Haeckel to place the medusa in the genus 

 Hybocodon. 



Haeckel apparently, judging from his references, lias only read 

 the description of the English species in the monographs b)" 

 Hincks and Allman. In these, the margin of the umbrella is 

 described and figured as occupying its normal position at right 

 angles to the longitudinal axis of the umbrella, and no mention is 

 made of the obliqueness of the margin of the umbrella of the 

 medusa whilst attached to the hydroid. But in the original papers 

 published by Hodge (1861) and by Allmau (1863.) on the hydroid 

 Corymoipha, the medusa is described with an oblique margin to 

 the umbrella ; it therefore corresponds with the description given 

 by Sars. Hodge gives figures of the medusse upon the hydroid, 

 and the margin is shown to be distinctly oblique. He not only 

 figures the medusae upon the hydroid but gives an excellent 

 figure of the free-swicnming form, just liberated from the hydroid 

 kept in his aquarium. The free-swimming medusa, as figured by 

 Hodge, has the margin at right angles to the longitudinal axis 

 of the umbrella ; therefore it cannot be oblique. Allman (1863), 

 in his original description of Corymorpha, on the development of 

 the medusa states : — " The four peripheral processes continue to 



