Ctenophora pulchella is distinct from species in Fragilaria, Synedra, and Ulnaria because of the relatively heavy silica cell wall, thick fascia and punctate striae in C. pulchella.

LM scalebar = 10 µm
Jkj  Ctenophora 696X46Modified Jkj  Ctenophora 12357X886Modified Jkj  Ctenophora 10858X795Modified Jkj  Ctenophora 9545X979Modified Jkj  Ctenophora 513X5 Jkj  Ctenophora 8456X776Modified
Length Range
46.5-90.8 µm
Width Range
4.3-7.6 µm
Striae in 10 µm

Also compare to

Ulnaria acus

(Kütz.) Aboal

Ulnaria ulna

(Nitzsch) Compère