1. Large, robust species, body length usually exceeding 26 mm; overall body form broad (Fig. 2), ratio of total body length/ body width across embolia falling in range of 1.50–1.65/1.00; posterolateral angles of pronotum highly produced and acuminate, ratio of maximum pronotal width/pronotal length along midline in submacropterous individuals falling in range of 3.78–4.21; male paramere shape as in Fig. 8.................................................................................... C. feana Montandon

– Slightly smaller and more elongate species, body length usually less than 26 mm; overall form more elongate (Fig. 2), ratio of total body length/body width across embolia falling in range of 1.74–1.95/1.00; posterolateral angles of pronotum only moderately produced, not highly acuminate, ratio of maximum pronotal width/pronotal length along midline in submacropterous individuals falling in range of 3.15–3.60............................ 2

2. Abdominal sternite V lacking a posteriorly directed medial tubercle; medial tubercle on sternite IV small and flattened, usually not projecting posteriorly over the base of sternite V when viewed laterally; preocular head 0.8 × the inner length of an eye or greater (Fig. 2); male paramere shape as in Fig. 10; northern Vietnam........................ C. tonkina new species

– Abdominal sternite V with a well developed, posteriorly developed medial tubercle, tip of this tubercle sharply angulate (Figs. 5, 6); medial tubercle on segment IV also well developed, raised and angulate (Fig. 6), often projecting over base of sternite V when viewed laterally; preocular head 0.7 X the inner length of an eye or less; Burma, Thailand, or northeastern India.. 3

3. Smaller species, body length less than 22 mm; medial tubercles on abdominal sternites IV and V not strongly produced posteriorly or projecting over basomedial sections of subsequent sternites (Figs. 5, 6); male paramere bearing a short, thumb-like process on basal half separated from main body of paramere by a deep incision (Fig. 7); Bramaputra River basin of northeastern India........................................................ C. assamensis Hope

– Larger species, body length exceeding 23.5 mm; medial tubercles on abdominal sternites IV and V produced posteriorly over bases of following segments when viewed laterally; male paramere lacking a short, thumb-like process on basal half separated from main body of paramere by a deep incision (Figs. 9, 11); Burma, Laos and Thailand........................................ 4

4. Anterolateral angles of pronotum strongly produced and spinose; male paramere lacking a deep notch at apex (Fig. 9); medial process of genital capsule notched at apex (Fig. 13); Burma and Laos.................................... C. birmaniensis Montandon

– Anterolateral angles of pronotum sharply angulate, but not strongly produced and spinose; male paramere bearing a deep notch at apex (Fig. 11); medial process of genital capsule with apex truncate, not notched (Fig. 15); Thailand and Laos............................................................ C. thailandana new species