Oct. 26, 1883.] 



• KNOV/LEDGE ♦ 



259 



Piscium, a fine and rathor close pair of very nearly equal 

 stars. This is shown in Fig. 66. \1/' Piscium, the small un- 

 named star to the soutli-east of rj Andromeda', on the 

 Map on p. 294, Vol. II., is another equal pair, l)ut 

 very considerably wider apart, and easily separable with 

 the lowest eye-piece, if is f Iso a very wide and easy star, 

 but in this case the components are unequal. The last 

 object identifiable from the map we are using is the leading 

 star in the constellation, a. This fine pair is represented in 

 Fig. 67. 



Fig. 67. Fig. OS. 



Before quitting this region of the sky we will just 

 direct our instrument to that lovely little pair i Trianguli, 

 which we inadvertently omitted while describing the con- 

 stellation Aries on p. 220 of Vol. I. of Knowledge. It is 

 not lettered in the Map to which we have so often referred, 

 but is the star over the letter U in "Triangula." Its 

 aspect is shown in Fig. 68. Its finely-contrasted colours 

 are unfortunately incapable of reproduction on a wood- 

 block. 



XoTE. — The engraver (licit i'or tlie first time) has failed to repro- 

 duce tlie different depths of shade in the drawing of the Lunar 

 Crater, Aristarchus, and Herodotus, on p. 122. As a slight and 

 partial correction, the student is recommended to pass a pale wash 

 of Indian ink over the interior of Herodotus. 



SEA ANEMONES 



AT THE FISHERIES EXHIBITION. 



By Thomas Kimber. 



VII.— THE PARASITE. 

 Actinia par(i!<ilica (Johnston). Actinia electa (Rapp). 



ACTINIA PARASITICA, though of large size and im- 

 posing apjiearance, and for a long period well known 

 on the shores of the Mediterranean, has but recently been 

 recognised as a British species. 



This anemone in its natural state inhabits deep water, 

 and is generally attached to some univalve shell. It is 

 believed that Parasitica never voluntarily selects an empty 

 shell, nor one occupied by the living niollusk ; but nearly 

 always one that is tenanted by the hermit crab {I'nf/arvs 

 Jiernliardiis.) Adult specimens almost invariably attach 

 themselves to old whelk-shells (Jlnrcimiin tnidalum). They 

 arc met with on tlie beach after storms, and the oyster- 

 dredge brings up shells invested with them, which are 

 thrown away liy the fishermen as refuse. 



The disk is yellowish white, tinged with purple near the 

 tentacles ; in form, slightly concave, like a saucer ; and 

 occasionally it is undulated. The radii (except the gonidal) 

 are not strongly marked. The cream-white mouth is raised 

 on a cone. 



The teutacula spring from the disk at about half-radius. 

 They are numerous, and roughly estiniated at •">00, arranged 

 in seven rows ; those in the innermost row being the 

 longest, which, when extended, are aboat an inch long and 



the eighth of an inch in thickness. In colour, they are 

 sometimes white, at others purple and white, and in some 

 cases tinged with cream colour. 



The column attains a height of four or five inches, and a 

 diameter of half its height. Dark -brown bands run from 

 the top to the bottom, and fainter transverse lines cross 

 the.se bands, forming a cancellated pattern, which is more 

 plainly visible on the upper part. Its normal figure has 

 been compared to a dice-box ; but it is constantly varying 

 its form, which is, however, very graceful at all times. 



Parasite should never be forcibly removed if it can 

 possibly be avoided, as specimens are often fatally injured 

 in the operation. 



The body when closed (in button form) resembles a 

 blunt sugar-loaf, handsomely coloured with buff, lilac, and 

 white. 



a. The Parasitic Anemone. 

 !). Whelk Shjll. ,-. Hermit Crab. 



This lovely and delicate creature also likes to be well 

 fed, and will not thrive without it Pieces of raw meat or 

 fish are eagerly devoured by it. 



In public a(iuaria, strict attention can seldom be given 

 to feeding, } et many actinia- will live for lengthened 

 periods under this regimen ; but they must and do 

 deteriorate. Many cases are recorded of extreme en- 

 durance when removed from their natural element. Mr. 

 Gosse narrates that a paraailica with other species were 

 placed in a jar with moist sea-weed without any water, and 

 kept imprisoned therein fur ten days ; they were then 

 restored to the aquarium in good condition, and showed no 

 sign of having sufiered from tlie treatment This strong 

 fact appears to prove that an international exchange or 

 transmission of sea anemones is quite practicable, and it 



