27 1 



SYSTEMATIC ACCOUNT 



ANTHOMEDUSAE 



Family CODONIDAE 



Genus Sarsia Lesson (1843) 



Generic characters. Codonidae with four similar, perradial tentacles, basal bulbs 

 each with an abaxial ocellus. Manubrium cylindrical, either within or extending beyond 

 the umbrella cavity. Gonads surrounding the manubrium in a single undivided mass. 

 Exumbrella without longitudinal rows of nematocysts. 



Sarsia gracilis Browne (Plate XIV, figs. 1-2; Plate XV, fig. i). 



Sarsia gracilis Browne, 1902, p. 275. 

 Sarsia gracilis Mayer, 1910, p. 60. 



Specific characters. Adult (Plate XIV, fig. i) : Umbrella cylindrical, nearly twice as 

 high as broad, with moderately thick walls, and a quadrangular margin. Manubrium a 

 cylindrical tube, about two-thirds of the length of the umbrella cavity. Gonads surround 

 nearly the whole length of the manubrium. Tentacles, four, about twice the length of 

 the umbrella, terminating with a large knob containing nematocysts. Ocellus on the 

 basal bulb of each tentacle. Colour: Manubrium, gonads, and basal bulbs of tentacles 

 of a pale yellowish brown. Ocelli bright reddish brown (specimens in formalin). 

 Size: Umbrella 5 mm. in height and 3 mm. in width (largest specimen). 



The earliest stage: Umbrella bell-shaped, just a little higher than broad. Manubrium 

 a cylindrical tube, about half the length of the umbrella cavity. Tentacles short, with a 

 large terminal cluster of nematocysts. Ocellus at the base of each tentacle. Colour: 

 same as adult. Size: Umbrella i mm. in height and about f mm. in width. 



Numerous specimens were taken in Stanley Harbour from November 1898 to 

 February 1899 and from November 1901 to March 1902. In addition some specimens 

 were obtained at Port Egremont, 28 October 1909 and at Roy Cove, i December 1909. 



Among the hydroids collected by Mr Vallentin in Stanley Harbour there is a species 

 of Syncoryne bearing medusa buds, some of which are well advanced and nearly ready 

 for liberation. They show the generic characters of the medusoid genus Sarsia. 

 Mr Vallentin kept a colony of this Syncoryne in an aquarium for a few days and obtained 

 from it a number of free-swimming medusae which he preserved for his collection. It 

 is probable, but there is no absolute proof, that the Sarsia liberated from the Syncoryne 

 develop into the adult form taken in the tow-net. 



The specimens taken in the tow-net form a good series of stages extending from the 

 earliest form up to the adult. The earliest free-swimming form is similar to those 

 liberated from Syncoryne, but it is well known that different species of Syncoryne 

 liberate medusae so much alike in their earliest stage that, at present, it is not possible 

 to distinguish one species from another with any degree of certainty. 



