Compare Craticula cuspidata
Compare
Craticula ambigua valves are abruptly narrowed at the apices, forming rostrate or subcapitate ends. In contrast, C. cuspidata is longer and wider than C. ambigua and differs in stria density (C. ambigua with 15-17 striae in 10 µm, C. cuspidata with 12-14 striae in 10 µm). Craticula pampeana is larger than C. cuspidata and is more rhomboid in shape, with a less distinct narrowing of the valve to rounded or rostrate ends. The axial area of C. pampeana remains narrow throughout the valve. Furthermore, stria density in C. pampeana is less (11-12 in 10 µm) than in C. cuspidata (12-14 in 10 µm). Another variety, C. coloradensis has ends that are more bluntly rounded than the ends of C. cuspidata. Craticula acidoclinata has a broadly rounded central area, compared to the slightly concave central area of C. cuspidata.
LM scalebar = 10 µm
Length Range
95-157 µm
95-157 µm
Width Range
24-36 µm
24-36 µm
Striae in 10 µm
12-14 transverse, 24-26 longitudinal
12-14 transverse, 24-26 longitudinal
Craticula coloradensis
Length Range
101-162 µm
101-162 µm
Width Range
22.5-26.7 µm
22.5-26.7 µm
Striae in 10 µm
transverse striae 11.9-14.3; longitudinal striae 20.0-23.8
transverse striae 11.9-14.3; longitudinal striae 20.0-23.8
Craticula ambigua
Length Range
38-75 µm
38-75 µm
Width Range
12-19 µm
12-19 µm
Striae in 10 µm
13-21 in the valve center, 17-21 at the ends
13-21 in the valve center, 17-21 at the ends