l60 PHILOSOPHICAL TKANSACTIONS. [aNNO 1751, 



to be 8 : and the use of them may be for the animal to catch and hold its food. 

 This part is not always to be observed, because it sometimes hides itself, by closing 

 up the trough (fig. h, s, s, t, c) about it; and thus it is safe in its habitation. 



As the figure of this animal bears no resemblance to the urtica marina, he can- 

 not see how we could class the polypus of the madrepora with the urtica. This 

 animal is extremely tender, and generally transparent, and very beautiful for its 

 variety of colours. He observed it in spring and autumn in the neighbourhood 

 of Rovigno and Orsera, where it is often fished up. 



A Description of the Miriozoon, or Pseudoforalium album fun gosum of Jldro- 

 vandm.* — As the size and shape of this polypary is sufficiently seen in fig. k, pi. 6, 

 he describes only what the microscope has enabled him to observe in it ; and what 

 Count Marsigli, though peculiarly diligent, has either overlooked, or examined 

 with too little attention. And the rather, as the mechanism of this body appears 

 very wonderful. 



Its substance is, rather like that of bone than of marble, but brittle : and its 

 brittleness proceeds from the great number of cellules with which it is hollowed. 

 These cellules are ranged all around in the branches, (fig. m) and disposed in 

 the manner of a quincunx; (fig. l, n, o) resembling those cinerary urns, fre- 

 quently found in Italy (fig. o). 



In each of these cellules lodges an oblong polypus (fig. a), slender at the tail, 

 (fig. a, t) thick at the belly, (fig. a, e) and again slender at the neck, (fig. a, s) 

 to which is attached a little cover, (fig. a, o, and p, o) round, concavo-convex, 

 and of a bony substance. This cover is attached by its lower part (fig. p, n) to 

 the entry of the cellule. 



When the polypus chuses to spread itself out, it opens the cover, and out of 

 its neck thrusts an ample proboscis (fig. k, g), in the shape of a cup ; and with 

 this it probably takes its food. There are two little muscles (fig. h, a, a) at the 

 lower part of this proboscis, which are attached to the cover. When the animal 

 returns into its nich, the proboscis sinks into itself; and the animal, by con- 

 tracting itself, draws back the cover ; and thus the cellule is perfectly closed, and 

 the creature secure in its retreat. 



However, all the polypi of this plant do not enjoy this conveniency and se- 

 curity, but only the adults; that is those which dwell about the, branches. As 

 for the others, that are not as yet adult, and live and lodge on the tops of the 

 branches, fig. l, r, n, n, and n, n, x) they have no covers ; and a considerable 

 number of them dwell in imperfect cells, or in such as are finished only in part, 

 (fig. D, t, t) and made of a sort of cartilaginous and membranaceous materials. 

 The imperfection of these cellules, and the weak consistence of the paste which 



* This coral is the Millepora tnmcata, Linn. 



