128 (115) Coiling of the flat side is partly obscured by 

 flaps from the inner ends of the chambers; 

 aperture is an arch on the periphery and 

 extends under the coalescing umbilical flaps. 

 Diameter 0.45-0.70 mm. a. Spiral view; b, 

 umbilical view; c, edge view Hanzawaia concenirica 



X60 



128 (115) Coiling of the flat side is exposed 129 



129 (12S) The coiled chambers are surrounded by annular 

 chambers. Diameter 0.80 mm or more, a, 

 Spiral view; b, umbilical view; c, edge view 

 Planorbidina acervalis 



X40 



129 (128) The coiled chambers make up the entire test 130 



130 (129) The umbilical side is involute; test is planoconvex; only the sutures of the spiral side are limbate; wall is more 

 coarsely perforate on the spiral (flat) side than on the umbilical (convex) side; aperture is a rimmed arch on 

 the periphery. Diameter 0.55-1.00 mm. a, Spiral view; b, umbilical view; c, edge view Cibicides lobatulus 



130 (129) The umbilical side is partly evolute; test is 

 strongly compressed; wall is coarsely porous. 

 Diameter 0.45-0.50 mm. a. Spiral view; b, 

 umbilical view; c, edge view Planutina mera 



X75 



42 



