1QI5.] J. Rircu1E: Aydroids of the Indian Museum. 551 
But Dr. Nelson Annandale, who kept examples of the hydroid 
alive in an aquarium for some time wrote in a note accompanying 
some of the specimens: ‘‘ The gonosomes, which develop into free 
medusae, are borne in a circle round the hydranth, below the 
tentacle’’; and again, in reply to a request for examples of the 
medusa or for further information ‘‘ I am sorry that I have not 
any specimens of the medusae of the little Hydroid from Port 
Canning. The only one I have seen escaped in my aquarium. It 
was so small that I could only just see it with a very powerful 
hand lens. ’’ 
In view of the minuteness of the structures concerned it is 
possible, but unlikely, that a naturalist even of Dr. Annandale’s 
acumen and experience, might have mistaken one of the planula- 
like buds to be afterwards described, for a medusa. 
In any case the elucidation of the sexual phase must be left 
to new collections of material gathered possibly at a different 
season of the year. 
II. ASEXUAL REPRODUCTION. 
Lateral Budding. 
A few hydranths possess lateral buds in various stages of 
development. The buds arise from the region below the tentacle- 
zone, and between it and the gentle narrowing which indicates the 
beginning of the stem-like basal prolongation. But they are not 
common on my specimens which were collected in the month of 
March, few hydranths possessing even a single bud, and two being 
the greatest number on any one hydranth. 
The buds are of the simplest structure (see plate xxx, fig. 4). 
They arise as small hollow projections of ectoderm and endoderm, 
which increase in length much more rapidly than in breadth. So 
there is formed an elongated hollow sac with thin walls of single- 
layered ectoderm and endoderm. The base of the sac becomes 
much constricted at its point of junction with the hydranth, but 
the internal cavity retains connection with the coelenteron of the 
hydranth by a narrow passage. In due course the connecting neck 
of the bud becomes ruptured, and the bud, which is now vermi- 
form and closely resembles the planula of many hydroids (except 
that it lacks cilia), breaks away and commences a free life. 
A released and therefore mature bud contains no traces of sex 
cells, and it must be assumed that it gives rise directly to a new 
hydranth. The only free example which I have observed seems 
recently to have broken loose from the hydranth (plate xxx, 
fig. 5). It is almost cylindrical in shape, 0°30 mm. in length by 
0085 mm. in maximum and 0'065 mm. in minimum breadth, 
slightly narrower in its median region and widening gently to its 
rounded extremities. The resemblance in shape to the planula 
of Cordylophora lacustris, as figured by Allman (1871, pl. iii, 
fig. 5a) is very marked. The proximal extremity still retains an 
opening representing the lumen which connected the bud cavity 
