;!.")s cumings and galloway morphology of trepostomata 



Intrazo(ecial Spines 



In a new species of Nicholsonella, N. cornula. Doctor Galloway dis- 



co\ered excessivel}^ minute, apparently hollow, spines projecting into the 



zooecial cavity. These are represented in figures 33 to 39, inclusive. The 



sphies are found only in the submature region, nearly always on the lower 



side of the zooecium and always curving do^vn toward the axial region. 



Tlie various appearances presented Ijy these spines are illustj-ateil in 1he 



figures. Figures 32, 34, and 36 show their appearance unde "."" , 



objective (X 65), and figures 33, 35, 37, and 38 under a 4 nv , ■^ 



(X 387). The spine usually has the appearance seen in fi 



end of the spine being bulbous and the wall appearing dou 



the spine were hollow and continuous with the thin liniii • -, , 



zooecium. Some of the spines in this species, however, f i , 



^ . I ? ' ,| or to para- 



spines in a nearly related species have the appearance re^t-i, i .^v]p 



and (/. figure 33, and n and m, figure 32 — that is, the sp ^ -, " ,• 



and appears solid. Either it is solid or the wall is so thii^.i 



'^ . . . than a nor- 



resolved by the very high magnification used. Most of the , ni . • 

 hollow, and such examples as are .shown in figure 38 coul i h o u 

 interpreted in any other way, for they not only appear ho^^^^^^j^^g ^^ 

 tain small particles of foreign matter, and moreover appear -^ • , <; 

 cate with pores in the wall (x in the figures). Some of th-, ■, <■ ii 

 tain a dark spot, resembling an air bubble, and it may veryL rpfio-PTit 

 these are actually bubbles (see figure 33, n). It is possible tli, poionie- 

 was originally solid, and that it 1:)ecame overlain by a seconds . 

 If the original spine, acting as the core, were perfectly transpu .^ • 

 appearances would be exactly the same as though the spine were origin..rp. 

 hollow. 



What possible function these spines could have had we do not ventu 

 to say. The nearest analogy among recent Bryozoa is found in the spin^ 

 figured and described by Nicholson in Ileteropora neozelanica (24). T 

 deed, the resemblance between his figures and our figure 32 is remarkably 

 strong. We have not been able to obtain any specimens of Heteropora 

 neozelanica. It is possible that the resemblances mentioned are without 

 significance, but they are interesting enough to warrant further study, 

 which we propose to give them nt our earliest opportunity. 



Wall Structure 



integrata and amalgamata 



The general characteristics of the wall structure of the Trepostomata 

 have been kno^wn ever since the classic work of Nicholson (22-25). We 



