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becomes quadrangular distally, with a thick cuticle, and the orifice is square. Collar very strong. 

 Three buds are given off typically from each zooecium ; ■ — one from the distal end of the 

 adnate part, and one from each side in the same region (exceptionally two on one side). 



The specimens here described were deeply embedded in the substance of a Monaxonid 

 Sponge, which had to be dissected away in order to exposé the Polyzoon. The variable character 

 of the peristomial region was probably the result of the conditions under which the Polyzoon 

 was growing; since the length and direction of the peristome would no doubt be dependent 

 on the extent to which the zooecium was immersed in the Sponge. 



In the youngest specimen drawn (fig. 2), the basal dilatation is represented by a triangular 

 swelling, in which a young polypide-bud is present. The terminal bud is already cut off by a 

 septum from the parent-zooecium. The lateral bud of one side is represented by a large pointed 

 process in which no septum has yet appeared ; while that of the other side is a smaller process 

 of the same kind which has not developed symmetrically with the other one. The peristome 

 has not yet made its appearance. 



In a later stage (fig. 1) the zooecium is Paludicc/la-\'\ke in shape; being represented 

 almost entirely by a pear-shaped portion which is continuous proximally with a very long 

 tube, of stolon-like form. The tube is, however, not a stolon in the proper sense, since it 

 gives off no buds; but is to be regarded, as in other similar cases, merely as the narrow 

 proximal end of the zooecium. The peristome is a short rounded elevation, much like the 

 corresponding part of a Paludicella-zoozcmm. This specimen shows a terminal bud, but only 

 one lateral bud. 



Fig. 8 represents a fully developed zooecium, in which the peristome is still very short, 

 but has the quadrangular form which is characteristic of the fully developed state. It will be 

 observed that this individual has no narrow proximal portion. The terminal and lateral buds 

 have been developed normally ; and it will be seen that the lateral buds originate in the 

 region of the distal part of the adnate portion ; an arrangement which may be noticed in other 

 dravvings. In some cases, however, as in fig. 3, the adnate part is hardly developed, and the 

 lateral zooecia then appear to be given off from the base of a long tubular, erect zooecium, 

 as in more typical species of Nolella. The varying length of the part which ma)- be considered 

 adnate is responsible for the varying position of the lateral buds, which come off from the 

 distal part of this region. 



Figs 6, 7, 4, 5 show various conditions of the peristome, intermediate between figs 8 

 and 3. The peristome may either come off at a distinct angle from the adnate part (fig. 7) 

 or may prolong its direction, with only a slight curve (fig. 5). In fig. 4 the zooecium is pear- 

 shaped ; the broader part being represented by the adnate portion of the zooecium and the 

 narrower end by the peristome. In all these cases, the quadrangular shape of the distal 

 part of the peristome is well marked, and is associated with a thickening of the cuticle in 

 this region. 



With the degeneration of the polypide further changes may take place. The quadrangular 

 form of the peristome is lost and the kamptoderm becomes everted as far as the base of 

 the collar, which projects freely to the exterior, though with some appearance of undergoing 



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