Plate 25 



Siniltina canui, new species 



Figure A: A young zoid tipped forward to show tlie lyrula and avicularium. Mandible 

 in place. Peristome incomplete as yet on left side, exposing avicularial tip. Scale a. 



Figure B: Most typical shape of mature secondary orifice. Lyrula broad. Beak tip ' 

 of avicularium not fully exposed. Scale h. 



Figure C: Young primary orifice showing part of one cardelle and the wide lyrula. , 

 Avicularial chamber has not yet formed on this individual, which is at the growing edge ■ 

 of the colony. Scale a. 



Figure D: Somewhat lateral view of young ovicelled zoid. Mandible in place on i 

 avicularium. Distinct transverse groove associated with development of avicularial ! 

 chamber still shows on this zoid just below peristome. Groove becomes obliterated exter- 

 nally in older zoids due to increasing calcification. Peristome has not yet encroached upon 

 sides of ovicell (cf. figure E). Scale a. 



Figure E: Growth habit. One zoid ovicelled. Ovicell marked by a raised mural rim 

 growing over it. Some ovicells show this feature, others do not. Left bottom zoid has two 

 zoid rows arising from it while right zoid has one. Scale c. 



Figure F: The secondary, heavily calcified, smaller, somewhat misshaped aperture of 

 an old zoid. Scale b. 



Figure G: Operculum. Scale a. 



Figures H, L J: Secondary orifices, variations in shape and size. The two lines extending 

 from each are mural rims or zooecial boundaries. Scale b. 



Figure K: Orifice of another young zoid tipped to show one cardelle and part of the 

 lyrula. The orifice is a bit lopsided because the peristome is not yet symmetrically com- 

 pleted. Avicularial chamber groove still present. Supporting the avicularium is a small 

 curved raised ledge, seemingly tilted forward. Scale a. 



1 



