Pupa: Not known.
Larva a small to medium bathophilus-type (about 11.7-14.1 mm: fem. 14.1 mm; male 12.0 mm); ventral tubules relatively long, anterior pair longer (ant. 1.44-1.56 mm; post. 0.96-1.40 mm). Sometimes a melanotus-type larva with posterolateral tubules slightly developed (up to 160 µm). Anal tubules size variable - dorsal 100-380 ݙm long (l/w 1.0-1.02), ventral 140-420 µm long (l/w 1.75-2.6).
Gular dark over more than the posterior half, frontoclypeus pale.
Mentum (Fig. c) with somewhat rounded teeth; c1 tooth relatively broad with c2 teeth closely applied, not well separated (type IB-IIA); 4th laterals slightly reduced (type I-II).
Pecten epipharyngis (Fig. a) with about 11 relatively broad, but irregular teeth. Ventromental plates (Fig. d) about 3.4 times wider than deep; 1.04 times the mentum width, and separated by about 43% of mentum width; about 33-36 striae; VMR 0.22-0.25.
Premandible (note can be seen across the central tooth of mentum in Fig. c) with outer tooth shorter (due to wear?) and inner tooth about four times the width of the outer tooth.
Antenna (Fig. b) with A1 about 1/3 the VHL and 2.93 times longer than wide, RO just below middle of A1; AR about 1.85; relative length of segments (micron): 111 : 30 : 9 : 13 : 8, i.e. A5 only a little shorter than A3.
Distance between the antennal bases greater than that between the S4 setae.
Mandible (Fig. e) with third inner tooth only slightly separated and darkened (type IA), about 16-17 furrows on the outer surface near the base and 10-11 taeniae in the Pecten mandibularis; Mdt-Mat 33 µm, MTR about 0.41.
Found: Saskatchewan - North Saskatchewan River (53.25°N, 105.08°W) (P.G.Mason).
Shows relationship to C. decorus Joh..