( 



Plate 12 



Cellarinella margueritae, new species 



(All figures except figure A were drawn with aid of camera lucida) 



Figure A: A typical colony, 47 mm. long. Nodes are white, undotted; intcrnodes are 

 stippled. The dots represent orifices. 



Figure B: Part of internode showing orifices of six zooecia. Three zooecia have external 

 avicularia pointing to the left, three to the right. Two mucros, one with an avicularium, 

 the other without, or "naked," are under each orifice, to the side. Scale a. 



Figure C: A young, lightly calcified zoid tipped forward so interior of orifice can be seen 

 better. Umbos not well developed yet. Diagonal oral ledge deep within the orifice shows, 

 as does external suboral avicularium. Scale b. 



Figure D: Looking down into primary orifice of a young zoid reveals relative position 

 of back ledge, frontal oral ledge, internal avicularium, external avicularium, and mucros. <, 

 Scale b. 



Figure E: Internal avicularium with opened mandible and diagonal frontal oral ledge t 

 as seen from inside of zooecium. Compare with figure H for approximate position in a a 

 zooecium. Scale c. 



Figure F: Two external avicularial mandibles with hooked tips and thinner oval area or 

 lucida. Scale c. 



Figure G: Orifice, mucros, and external avicularium. The two crossing dotted lines s 

 enclose the approximately 110° angle at which the avicularium is bent. 



Figure H: Interior of a broken-away frontal wall shows several zooecial cavities and J 

 parts of two ovicelled zoids. The internal avicularia are obliquely directed. Two ovicells s 

 are exposed, also the very thick frontal wall, porous in places. Scale a. 



Figure I: Transverse section stereogram through parts of three zooecia. Zoid at extreme 

 left is cut through to show diagonal frontal oral ledge and inner avicularium. Lower right I 

 zoid is cut to show deep down its end (proximal) wall with sieve plate, over which project t 

 two calcareous processes. Pore plate identifies lateral wall. Scale b. 



Figure J: Transverse section through a zooecium at level of sieve plate and back ledge, 

 looking up at distal or end wall. Note thickness of frontal wall as compared with other r 

 walls, also its channeled nature. Scale b. 



Figure K: Set of old, heavily calcified processes which occur over a sieve plate in end 1 

 wall of a zooecium. Scale c. 



Abbreviations used on plates 12-18 



AC, avicularial chamber LW, lateral wall 



AR, areolar pores MA, mandible 



BC, zooecial cavity MS, muscle fibers 



BK, beak of avicularium MU, mucro or umbo 



BL, back ledge NO, node 



BW, back wall NZ, nonovicelled zoid 

 CH, channels or canals leading in from frontal OL, olocyst 



pores OR, orifice or zooecial aperture 



CP, calcareous processes OV, ovicell 



CR, chitinous rootlets PP, pore plate or rosette plate 



FL, frontal oral ledge PV, peristomial visor 



FP, frontal pores SA, external avicularium 



FW, frontal walls SL, second calcareous layer or tremocyst 



lA, internal avicularium SO, secondary orifice 



IN, internode SP, sieve plate of end wall 



