| Thin at both ends | 
|   N. acicularis
 92 x 4 μm
 Nishi-Urawa
 Saitama, 2003
 |   N. acicularis
 78-92 x 3 μm
 Kuroiso
 Tochigi, 2001
 |   N. acicularis
 88 x 4 μm
 Hirai river
 Akiruno
 Tokyo, 2004
 |   N. acicularis
 87 x 4 μm
 Shinobazu-ike
 Tokyo, 2001
 | 
|   N. acicularis
 86 x 4 μm
 Jizoh-bori
 Sannoh Park
 Saitama, 2005
 |   N. acicularis
 59-81 x 3 μm
 Japan, 1997
 |   N. acicularis
 72 x 4 μm
 Japan, 1999
 |   N. acicularis
 71 x 4 μm
 Omoi river
 Oyama
 Tochigi, 2004
 | 
|   N. acicularis
 63-69 x 3.5 μm
 Uruguay, 1999
 |   N. acicularis
 52-62 x 4 μm
 Sendabori
 Chiba, 2002
 |   N. acicularis
 57 x 4 μm
 Tama river
 Chofu
 Tokyo, 2004
 |   N. acicularis
 61 x 3.5 μm
 Usui river
 Takasaki
 Gunma, 2004
 | 
|   N. acicularis
 55 x 4 μm
 Karasu river g.l.
 Fujioka
 Gunma, 2004
 |   N. acicularis
 53 μm
 Chiba-Minato p.
 Chiba, 2003
 |   N. acicularis
 45-68 x 3 μm
 Tachikawa
 Tokyo, 2004
 |   N. acicularis
 88 x 4 μm
 Hirose athletic p.
 Kumagaya
 Saitama, 2004
 | 
|   N. acicularis
 62 x 3 μm
 Iruma river
 Sayama
 Saitama, 2004
 |   N. acicularis
 68 x 3 μm
 Owada Park
 Saitama, 2005
 |   N. acicularis
 84 x 3 μm
 Nagaike park
 Hachioji
 Saitama, 2005
 |   N. acicularis
 57,62 x 4 μm
 Asa-kawa
 Hachioji
 Saitama, 2005
 | 
|   N. acicularis
 88 x 3 μm
 Oura central p.
 Oura
 Gunma, 2006
 
  |   N. acicularis
 88 x 3 μm
 near Sakitama-kofun
 Gyoda
 Saitama, 2006
 
  |   N. acicularis
 56 x 3 μm
 Binnuma-gawa
 Fujimi
 Saitama, 2006
 
  |   N. acicularis
 70 x 4 μm
 Jionji-shinsui p.
 Iwatsuki
 Saitama, 2006
 
  | 
| Relatively thick at both ends | 
|   N. acicularis
 62 x 4 μm
 Japan, 1999
 |   N. acicularis
 55 x 5 μm
 Iruma river
 Kawagoe
 Saitama, 2004
 |   N. acicularis
 78 x 4 μm
 Shinobazu-ike
 Tokyo, 2001
 |