| 
Inner side slightly concaved; L/W=7-14 | 
| 
Cell body 20-40 μm in width | 
 
	 var. acerosum
	 508 x 37.5 μm
	 L/W=13.5
	 Koaze river
	 Saitama, 2002 | 
 
	 var. acerosum
	 508 x 32 μm
	 L/W=16
	 Saitama, 2000 | 
 
	 var. acerosum
	 363 x 36 μm
	 L/W=10.1
	 Saitama, 1999 | 
 
	 var. acerosum
	 314 x 34 μm
	 L/W=9.2
	 Motoyurugi
	 Fujioka
	 Gunma, 2004 | 
 
	 var. acerosum
	 206 x 38 μm
	 L/W=5.4 ?
	 Saitama, 1999 | 
 
	 var. acerosum ?
	 560 x 34 μm
	 L/W=16.5
	 Yamato
	 Kanagawa, 2003 | 
 
	 var. acerosum ?
	 530 x 35 μm
	 L/W=15
	 Ina town
	 Saitama, 2003 | 
 
	 var. acerosum
	 450 x 34 μm
	 475 x 34 μm
	 L/W=13, 14
	 Saitama, 1999 | 
 
	 var. acerosum
	 470 x 37 μm
	 L/W=12.7
	 Akasaka-numa
	 Iwatsuki-ku
	 Saitama, 2006
	
   | 
 
	 var. acerosum
	 388 x 38 μm
	 L/W=10.2
	 Akasaka-numa
	 Iwatsuki-ku
	 Saitama, 2006
	
   | 
 
	 var. acerosum
	 338 x 33 μm
	 L/W=11.8
	 Saitama, 2001 | 
 
	 var. acerosum
	 334 x 27 μm
	 L/W=12.4
	 Nanbata castle p.
	 Fujimi
	 Saitama, 2004 | 
 
	 var. acerosum
	 338 x 28 μm
	 L/W=12.1
	 Kaga
	 Ishikawa, 2000 |