PLATE 11 



Fig. 1 Stomaclietosella siiiuo.sa, young zooecia at margin of colony. 



Fig. 2 The same, secondary calcification. 



Fig. 3 Eippopodinella hippopus, young zooecia at margin of colony and 

 beginning of secondary calcification. 



Fig. 4 The same, somewhat older zooecia. 



Fig. 5 Rliamphostomella ovata, young zooecia. 



Fig. 6 The same, highly calcified. 



Fig. 7 Umbonula arctica, young zooecia. 



Fig. 8 Mucronella immersa 



Fig. 9 Smittina reduplicata n.sp., advanced stage of calcification. Three con- 

 ditions of the secondary oral avicularium are shown, median (usual) and lateral 

 and bilateral (unusual). The surface is exceedingly rough. 



376 



