1904 - 5 .] Report on Medusae found in Firth of Clyde. 771 
end of September. It never became abundant, and was only 
occasionally taken after the middle of June. 
Obelia nigra may be easily distinguished by the presence of 
dark brown or blackish bulbs at the base of the tentacles. 
Octorchis gegenbauri, Haeckel. (Tables I. 25 ; II. 24.) 
Octorchis gegenbauri , Haeckel, 1879, p. 171, taf. xiii. 
In 1901, a single specimen was taken on 30th September. 
In 1902, a single specimen was taken on 15th November. 
Description of the specimen taken on 30th September : — 
The stomach is on a long peduncle. The gonads are just 
beginning to develop upon the radial canals in about the middle 
of the peduncle, and also upon the radial canals on the sub- 
umbrella. Four perradial tentacles and many marginal bulbs, 
most of which have one cirrus, and a few have two cirri. Eight 
marginal sense-organs, each with three to five otoliths. 
Colour. — The gonads, tentacles, stomach, and marginal bulbs 
have a yellowish tinge in transmitted light. 
Size. — Umbrella 5 mm. in length and 8 mm. in width. 
This is a rather rare medusa on the British coast. Distribution : 
Cornwall and Devon, west coast of Ireland, Mediterranean. 
Phialidium buskianum (Gosse). (Table II. 21.) 
Thaumantias buskiana, Gosse, 1853, p. 385, pi. xxii. figs. 5-11. 
Phialidium buskianum , Browne, 1896, p. 448, pi. xvi. fig. 6. 
In 1902, it was fairly common at the end of September, and 
was occasionally taken during October. It was last seen on 
15 th November. 
Phialidium cymbaloideum (van Beneden). (Tables I. 22 ; 
II. 13.) 
Phialidium cymbaloideum , Browne, 1896, p. 491, pi. xvii. 
In 1901, it was occasionally taken from 20th July to 15th Oct. 
In 1902, it was occasionally taken from 20th May to 11th Oct. 
This medusa is liberated from a hydroid belonging to the genus 
Campanulina. It is figured in Hincks’s monograph (pi. 38, fig. 1), 
