RADIATA. 35 
been originally two inches in diameter, and that had somehow contrived to 
swallow a valve of Pecten maximus of the size of an ordinary saucer. The 
shell, fixed within the stomach, was so placed as to divide it completely 
into two halves, so that the body, stretched tensely over, had become thin 
and flattened like a pancake. All communication between the inferior 
portion of the stomach and the mouth was, of course, prevented; yet. 
instead of emaciating and dying of an atrophy, the animal had availed itsel! 
of what undoubtedly had been a very untoward accident, to increase its 
enjoyments and its chances of double fare. A new mouth, furnished with 
two rows of numerous tentacula, was opened upon what had been the base, 
and led to the under stomach ; the individual had, indeed, become a sort of 
Siamese twin, but with greater intimacy and extent in its unions!” 
The Actiniz are hermaphrodite ; the reproduction is both by division and 
by eggs; and the eggs or young (as the case may be) are ejected through 
the mouth, or rarely, by a kind of abortion, through the tentacles, according 
to Contarini. The young do not differ essentially from the adult, the chief 
difference being in the small number of their tentacles. 
The Actiniz reproduce lost parts, especially the tentacles, with great 
facility ; and when the body is cut into two, three, or even four parts, each 
may survive and become a complete animal. If the section is horizontal. 
the lower part acquires a new mouth and tentacles, and the upper part a 
new base, although in one instance the latter produced a second mouth, so 
that food was taken at both extremities of the new animal. These 
experiments indicate that the base has the greatest vital power. (See 
Contarini, 7rat. delle Attinie, &c., Agassiz’s Lectures, and Johnston’s Zooph. ) 
Actiniz will survive after being placed in water hot enough to blister the 
skin, and they may be frozen and thawed with impunity, but immersion for 
a few minutes in fresh water kills them. 
The order Actinoida contains the sub-orders Actinaria and Aleyonaria, 
and the families, according to Dana, are as follows: 
SvuB-ORDER 1. ACTINARIA. 
Often coralligenous, cells lamelliradiate. 
Tribe 1. Astreacea. 
Many tentacles in imperfect series ; coralla calcareous, with multiradiate 
cells, with the lamellee extending beyond the cells. 
Fam.1. Aectinide. Not coralligenous, usually attached, but sometimes 
floating in the sea. Actinza (pl. 77, figs. 5, 8). Lucernaria (pl. 76, fig. 72). 
(Johnst. Zooph., p. 228. KR. An. pl. 68, with anatomical details.) 
Fam. 2. Astreide. Coralla calcareous, tentacles marginal, coralla with 
excavate cells, stars circumscribed. Astrea astroites (pl. 75, jig. 62). 
Meandrina labyrinthica, Linn. ( pl. 75, jig. 64); hemispherical, with long 
winding lines: American seas. 
Fam. 3. Fungide. Disks not circumscribed, tentacles scattered, short, 
or obsolete; simple or aggregate-gemmate; when aggregate the disks are 
confluent ; surface of the coralla stellate, without proper cells. /ungia 
fungites, Linn. (pl. 75, fig. 65), has a circular coral, with radiating 
lamelle, like the under surface of some mushrooms; beneath granulated. 
239- 
