8 
JList of the Contents of each Tank. 
Tank No. 
20 , 
in colour. The dirty colour of the water is due to 
the ink they shoot out when disturbed. 
Pelagic Animals (see Note on p. 26). These show best 
in bright sunshine (from noon to two); many do not 
live long, and the tank is richest after a calm dull day. 
The more delicate are in wide glass cylinders. There 
may be: Jelly-fish. A. Medusae (p. 21). Cotylorhiza 
(from September to January), nearly a foot across, like 
a mushroom with a cauliflower for its root. Rhizo- 
stoma , as large, a beautiful white globe with a violet 
border and a swelling violet and white stalk. Car- 
marina, two or three inches long, umbrella-shaped, 
perfectly transparent, with four long fishing-lines. 
B. Ctenophora (p. 26), have each eight lines of 
moving paddles which look like running beads of 
light. Beroe , one to three inches long, shaped like 
a bishop’s mitre; a most delicate pink. Eucharis , 
much broader base with rounded projections, quite 
transparent. Venus’s Girdle ( Cestus ), a transparent 
ribbon about an inch broad. C. Siphonophora (p. 25), 
generally like transparent filmy flowers on a central 
stalk. — Pelagic Tunicates. Salps (p. 65). Each 
animal consists of a transparent swimming barrel, 
from one to eight inches long; it is easily recognised 
by the globular brown kernel in one corner; often 
the salps adhere side by side to form chains. *Pyro- 
soma (p. 64), a transparent frothy cylinder up to 
eight inches by three. Sometimes small specimens 
contain the shrimp-like Crustacean Phronima (p. 47). 
— Mollusks. A. Heteropods (p. 57). Pterotrachea has 
a long proboscis and sculls itself rapidly on its back; 
somewhat similar is the allied Carinaria , less trans¬ 
parent and with a small shell. B. Pteropods (Sea- 
butterflies, p. 58), flap a pair of transparent wings. 
Besides these pelagic animals there are outside 
the cylinders various small Octopods (p. 48), and 
crawling Mollusks, such as Tethys (p. 56), as large 
as a hand, spotted with red and brown, Doris (p. 56), 
as large as a thumb, a tuft at one end, etc. 
Fishes. Sea-horse (. Hippocampus , p. 80), head like the 
knight in chess, tail curling forward, generally at- 
