1904-5.] Report on Medusce found in Firth of Clyde. 751 
broad dome-shaped mass of jelly. The velum is rather narrow. 
Upon the ex-umbrella there are four perradial channels, running 
from the basal bulbs of the tentacles to about half way up the 
umbrella ; the channels contain nematocysts. The stomach is 
upon a short peduncle, and the mouth is small and circular. Four 
radial canals. Upon each canal there is a slight linear swelling, 
occupying the central part of the canal and about one-third of its 
length. It is similar to the swelling found upon the radial canals 
of Dipurena halterata. There is no evidence at present that these 
swellings are immature gonads ; they are simply thickenings of the 
endoderm. The gonads surround the stomach, forming a large 
swelling, which is separated into four parts by perradial ridges. 
(The specimen is a female, and the large ripe ova project in a 
most conspicuous manner.) The four tentacles are uniform in size, 
and have along their outer side a double row of nematocysts, like 
those figured by Allman for Gemmaria implexa, with two tentacles. 
The basal bulbs of the tentacles are globular, and are without an 
ocellus. 
Colour. — Basal bulbs of the tentacles have a bright crimson 
centre, and along each tentacle extends a central orange line. 
Size. — Umbrella l - 5 mm. in length and 1*75 mm. in width. 
Hippocrene pyramidata, Forbes and Goodsir. 
(Tables I. 20 ; II. 23.) 
Hippocrene pyramidata , Forbes and Goodsir, 1851, p. 312, pi. x. 
Margelis pyramidata, Browne, 1900, p. 709. 
In 1901, a single specimen was taken on 20th July and another 
on 2nd October. 
In 1902, a specimen was taken on 6th November. 
This is rather a rare species. It was first found by Forbes and 
Goodsir off Mull, and by Haeckel at Handa Island, on the west 
coast of Scotland. I have also taken a few specimens at Port Erin 
and in Valencia harbour. 
Description of the specimen taken at Millport on 2nd October 
1901 : — The umbrella is semi-globular, about as high as broad, and 
very thick ; the upper half of the umbrella is a thick mass of jelly. 
The stomach is situated upon a short, broad, cone-shaped peduncle, 
