1896. ] BRITISH HYDROIDS AND MEDUS&. 461 
results with hydroids and meduse have been obtained when the 
specimen has been killed by a fixing reagent, and then placed first 
into a 22 p. c. solution and finally into a 5 p. c. solution of form- 
aldehyde. 
IT owe my sincere thanks to Professor Weldon for allowing me 
the use of a table in his Research Laboratory at University College, 
and for the aid and kind advice which he has so often generously 
given. To Mr. E. J. Allen, Director of the Marine Laboratory at 
Plymouth, I am indebted for his kindness in arranging expeditions 
for the collection of specimens during my visit to Plymouth. 
Parr I.—HYDROIDS AND THEIR MEDUSA. 
(Hyprorpa GYMNOBLASTEA.) 
In the first part of these notes the Medusew come under their 
hydroid names, and are arranged according to Allman’s classifi- 
cation. The synonyms are divided into two sets: the first set 
contains the names given to the hydroid form, and includes, also, 
the references,to the medusa whilst attached to the hydroid, or 
reared from the hydroid in confinement. The second set of 
synonyms refers only to free-swimming meduse taken in the sea, 
which have been usually described under other names. 
Fam. SYNCORYNIDA. 
GEMMARIA IMPLEXA (Alder). 
Tubularia implexa, Alder (1857). 
Coryne pelagica, Alder (1857). 
Coryne briareus, Allman* (1859). 
Coryne implewa, Wright (1859); Alder* (1861). 
Zanclea implexa, Allman* (1864) ; Hincks* (1868). 
Gemmaria impleaa, Allman* (1872); Haeckel* (1879). 
* References marked with an asterisk denote that medusa-buds upon the 
hydroid are also referred to. 
Two specimens of the medusa were taken at Plymouth on 
Aug. 31st, 1895. Both were about 1 mm. in diameter, and corre- 
sponded to the figures given by Allman in his monograph. The 
hydroid form has not yet been recorded for the South of England. 
The medusa of Gemmaria implexa is very much like a medusa 
described by McCrady as Gemmaria gemmosa, found in Charleston 
Harbour, U.S.A. 
Disrrizurion. Scotland—Forfarshire, Allman (H'). Firth of 
Forth, Wright (H); Allman (11). 
England—30 miles E. of Holy Island, Alder (H). Cullercoats, 
Alder (H); Seaham Harbour, Hodge (H); Plymouth, £. 7. B. 
(M’). 
1 H = Hydroid form, with or without medusa-buds. 
M = Free-swimming medusoid form only. 
