1(3 Edward T. Browne. [Xo. 4 



The young medusa when budded off is about 1 mm. or less in 

 length; the largest specimen in this collection is 3 mm. in length, 

 nearly the size of a full grown adult, and shows no signs of a 

 further increase in the number of interradial tentacles. 



This medusa is very common during the spring on the British 

 coasts. As a rule the young medusa starts its free swimming life 

 with either two or three tentacles in each interradial group, and 

 early stages with solitary interradial tentacles are very rarely seen. 



It is unfortunate that there are only three specimens in the 

 collection. as it would be of interest to know for certain whether 

 the presence of solitary interradial tentacles at birth is a constant 

 feature. If so, the British Margellium octopunctatum is evolving a 

 new character. 



Leptomedusae. 

 Obeli a nigra, Browne . 

 Obelia nigra, Browne, 1900, p. 721. 



Hjeltefjord. 0—50 m. 6. 4. 1898. . 



An early stage with about 45 tentacles. Umbrella about l 1 /* 

 mm. in diameter. 



Hjeltefjord. 0—245 m. 25. 4. 1901. 



Five specimens belonging to the intermediate and adult stages. 

 The largest one has 124 tentacles- and measures 3 1 / 2 mm. in dia- 

 meter; the gonads ripe and the ova large. 



Off Herlø. 0—160 m. 28. 3. 1901. 



An early stage. 



Osund. Surface. 12. 4. 1901. 



Seven specimens belonging to the intermediate and adult stages. 



This species is very common on the British coasts and during^ 

 the summer months large shoals are not unfrequently met with. It 

 has, no doubt, been often recorded under the name of Thauman- 

 tias (Obelia) lucifera of Forbes, from which it may be easily di- 

 stinguished by the fact that some of the tentacles have large black 

 basal bulbs. 



The following is a copy of the original description of the Adult: — 

 Umbrella slightly curved; stomach short, with a quadrangular base, 

 and with a- small cone-shaped (apical) process in the substance of 

 the umbrella; mouth with four lips; eight marginal sense-organs, 

 with a single otolith in each. Tentacles, 150 — 200. The basal 



