I04 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [BulL 



broad band at sides of abdominal segments two to four 

 and spot at sides of segment five, white. Length i6 mm. 



semidea 

 Tibiae black 2 



2. Abdominal segments never marked with white 3 



Abdominal segments always marked at sides with white 5 



3. Abdomen steel blue 4 



Abdomen for the most part rufous (male) . .americana var. laportei 



4. Wings for the most part hyaline; body steel-blue, with tarsi 



and antennae beyond second segment yellow; head and 

 thorax clothed with long black hairs (male). Length 20 

 mm americana 



5. Abdomen almost wholly steel-blue, with obscure spots on 



each side of fifth or fifth and sixth abdominal segments ; body 

 steel-blue, with the tarsi and the antennae beyond the second 

 segment, yellow; head and thorax more or less covered 

 with long black hairs. Length 20-25 mm. (female) . .americana 

 Abdomen steel-blue, with three or more distinct white spots 6 



6. Abdomen with a white spot on each side of third, fourth, 



and fifth segments; wings violaceous (female) 



americana var. nortoni 

 Abdomen with more than three segments marked with white 7 



7. Abdominal segments marked with small rounded spots.* 8 



Abdominal segments marked with broad transverse bands... 9 



8. Abdomen with white spots on each side of segments two to five; 



wings violaceous (female) americana var. luctifera 



Abdomen with white spots on each side of segments two to six; 

 wings hyaline (female) americana var. decimaculata 



9. Abdomen with white bands on segments two to six; wings 



violaceous (female) .americana var. dahlbomii 



Abdomen with white bands on segments two to seven, fre- 

 quently meeting at middle; wings hyaline (female) 



americana var. alba 



°C. semidea Cresson. 



C. americana var. laportei LePeletier. New Haven (F. E. 

 Willits). 



C. americana Leach. Hov^ard, Insect Book, PI. xii, Fig. 4 

 (male), Fig. 44, p. 74 (female). Larva feeds on willow, 

 elm, poplar, alder, maple, and linden. Connecticut (E. N.) ; 

 New Haven, 2 June, 1904 (H. L. V.) ; Woodmont (W. E. B.) ; 

 Stonington, August, 1907 (G. H. Hollister). 



*C. americana var. nortoni MacGillivray. Howard, Insect 

 Book, PI. xii, Fig. i. Connecticut (E. N.). 



°C. americana var. luctifera Kirby. 



