Plate 17 



Cellarinella roydsi, new species 

 (For explanation of abbreviations see key for plate 12. All figures drawn with aid of camera luclda) 



Figure A: Part of node, internode, and lateral border of a colony. Macros jut ouJ; 

 prominently from frontal just under orifices. External avicularia missing from two lowesi; 

 zooecia. Frontal oral ledge and internal and external avicularia show clearly in most c 

 zoids. Scale a of plate 14. 



Figure B: Two young, lightly calcified zoids. Zoid at right shows partial!}' calcifiei 

 ovicell wall within the orifice. This wall calcifies by degrees and in sections, as shown' 

 Scale e of plate 14. 



Figure C: Sagittal section through upper part of ovicelled zoid and parts of its neighbors: 

 Lower lateral wall has two types of perforations — rosette plates and rows of single porci 

 Scale c of plate 14. 



Figure D: Sagittal section through an ovicell, orifices, internal a\icularial chamber, am 

 the peristomie (the heavily stippled passageway between primary and secondar\' orifices; 

 Although this colony fragment was completely dry, the mandibular muscles in avicularifi 

 chamber were still plainly discernible. Scale d of plate 14. 



Figure E: Looking down into orifice of a young, lightly calcified zoid to show key characa 

 ters — the diagonally directed frontal oral ledge and the prominent, highly placed curve 

 beak of internal avicularium. Scale e of plate 14. 



Figure F: A cross section of several zooecia. The uppermost zoid, just under fronta; 

 wall, is cut through the level of frontal oral ledge, back ledge, and internal aviculariuni 

 Zoid beneath it is cut at level of its proximal end wall, sieve plate, and two calcareomi 

 processes. The other boxlike zoids are cut at various levels between the preceding tWCT 

 Scale r of plate 14. 



Figure G: A young, lightly calcified zoid with two external avicularia and a mucrc 

 between them. This is a rather uncommon condition, the rule being the presence of oa 

 external avicularium. Zoid has been tipped forward so its orifice can be more plainly seerc 

 Scale e of plate 14. 



Figure H: Another very young, lightly calcified zoid seen from front. Lateral positio 

 of the nonaviculariate mucro and transverse direction of the suboral external aviculariur 

 are typical for species. Avicularial beak is pointed and hooked. Scale e of plate 14. 



Figure I: Mandible of an external a\icularium. A slight hook is barely indicated a 

 tip. Var}'Ing degrees of chitinizalion, the darkest parts are the most heavih' chitinizec 

 Scale /of plate 14. 





