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to provide for the formation of the ova, and of them alone ; in which 

 case is it not allowable to suppose that the nutrition of the whole 

 aggregate animal, that is of each distinct series, is in some way 

 connected with the more persistent nature of the cups? 



This must, however, be left undecided, and I will proceed to 

 describe more minutely the structure of the cups and cells and their 

 contents. First, of the cups, which constitute the great peculiarity of 

 this species, and which, as Dr. Johnston suggests, are clearly the 

 analogues of the " bird's-head processes " in other Bryozoa, and with 

 which, in fact, they exactly correspond in structure. The rudi- 

 mentary cups (as they may be termed) in Laomedea obliqua, can 

 hardly be deemed in any way analogous to the curious organs 

 in question ; at all events, they present nothing of the same structure, 

 as might be supposed upon considering the absolute distinction of the 

 classes of animals to which the Campanulariada and Bryozoa re- 

 spectively belong. In form, as stated by Ellis, they resemble the 

 bowl of a tobacco-pipe placed upon a short stem. The walls of the 

 cup are tolerably thick, but brittle and opaque, from the abundance 

 of calcareous matter contained in them, and which is present in 

 greater quantity in them than in any other part of the polypidom. 

 The mouth of the cup, which is directed upwards, has a sinuated 

 margin, rising anteriorly into a sharp, curved beak, like that of the 

 cuttle-fish, or hawk -billed turtle : when the earthy matter is dis- 

 solved away by acid, this beak is found to be formed principally of a 

 horny substance, and it will be seen to be supported and rendered 

 more firm by the anterior wall of the cup, from which it rises, being 

 strengthened by the same material. The posterior edge of the cup is 

 even and semicircular, and about midway between the front and back 

 of the cup, the lateral margins rise up on each side into a small eleva- 

 tion, for the articulation of a movable beak or mandible. This beak, 

 when viewed laterally, appears curved and sharp pointed, and when 

 viewed en face, presents the form of an equilateral triangle, (fig. 4, d). 

 It is formed of a firm, horny framework, the interior space of which is 

 filled up with a membrane, in the centre of which, or rather nearer 

 the apex of the triangle than its base, may be observed a small trans- 

 parent spot, indicating the point of attachment of the tendon of the 

 muscles by which the mandible is depressed or closed. The base of 

 the triangle reaches across from one side of the cup to the other, and 

 the mandible is articulated to the sides of the cup by the two angles 

 of the base. A flexible membrane connects the base of the mandible 

 to the posterior lip of the cup, and thus completely closes the orifice 



