Plate 22 



Rhamphostomella bassleri, new species 



Figure A: Ovicelled zooecium with two central frontal avicularia in addition to the cus-: 

 tomary oral one. Above it is part of a zooecium that has a single frontal avicularium in 

 the lower position. Note the two small, round pores generally associated with the orai 

 avicularial chamber, below and to the back of it. Drawn to the 0.3 mm. scale at left. 



Figure B: Nonovicelled zooecium with two frontal avicularia in still different positions. 

 Only the secondary orifice shows in this as well as in figures A and C. Same scale as figure A.i 



Figure C: Another zooecium with two frontal avicularia placed very proximally. The 

 oral avicularium faces in the opposite direction from the preceding two figures. Same scale, 

 as figure A. 



Figure D: Side view of two zooecia; lower one with the oral avicularium facing observer, 

 upper left one with the avicularium also mounted on a mucro but facing away from observerl 

 with onl\' the mucro showing. Same scale as figure A. 



Figure E: Looking down into the primary orifice of a zoid. Upper left part of primary 

 orifice is obscured by a growing peristome. Lyrula and cardelle are typical. Oral avicula-; 

 rium is just below the lyrula, externally. Drawn to the 0.2 mm. scale at left. 



Figure F: Oral avicularium with open mandible obstructing the secondary orifice.i 

 Same scale as figure G. 



Figure G: Oral mandible. Drawn to the 0.1 mm. scale at right. 



Figure H: Operculum flattened out. Same scale as figure G. 



Figure I: A smaller oral mandible showing the typical tip curvature. Same scale as 

 figure G. 



Figure J: Another small oral mandible. Drawn to the 0.1 mm. scale at right. 



Figure K: Frontal avicularium. Mandible heavily outlined. Drawn to the 0.1 mmi 

 scale at right. 



Figure L: Nonovicelled young zoid showing part of the primary orifice, the growing 

 lateral wings of the peristome and the beginning of the unilateral oral avicularial chamber- 

 Same scale as figure N. 



Figure M: Another operculum, not flattened out but in normal position on zoid. Lowen 

 border of membrane is indefinite. Same scale as figure G. 



Figure N: Interzooecial distal wall, somewhat inverted V-shape. Cellular debris (dark 

 material) found in a number of zoids in adoral chambers. Drawn to the 0.2 mm. scalt 

 at left. 



Figure O: Ovicelled zoid without any frontal avicularium. Oral avicularium bidder 

 by position of the mucro. Secondary orifice typical. Low oval frontal pit or depressior, 

 present on some of the ovicells. Same scale as figure A. 



Note: Figures A, B, C, and O are from paratype colonies encrusting "Rock 3." Figure! 

 D-N are from free foliaceous holotype colony from Station 190. 



