1895.] NATUBAL SCIENCES OF PHILADELPHIA. 355 



7. Thorax entirely black, including the sides; abdominal spots small, 

 widely separated, the fifth and sixth segments not spotted. 



cinerea. 



Thorax more or less yellow on the sides 8 



8. Mesopleime spotted 9 



Mesopleune not spotted Spiuolce. 



9. Clypeus entirely yellow ; form elongate 10 



Clypeus with two black spots basally ; form shorter and 

 more robust texana. 



10. Markings of abdomen narrow, separated within ; mesopleurse 



with two small spots amoena. 



Markings of abdomen broad, united within; mesopleurse with 



a large spot covering about half its area connexus. 



11. Thorax at the most clothed with a thin, pale pubescence, 



more or less yellow on the sides 12 



Thorax densely pruinose, not spotted on sides; markings of 

 abdomen broad, united internally, greenish-white . . pruinosa. 



12. Dorsulum and abdomen densely clothed with pale pubes- 

 cence, that on abdomen shortest troglodytes- 



Dorsulum clothed with pubescence on anterior portion only, that 

 on abdomen not dense, but rather indistinct similans. 



13. Clypeus with two black spots basally texana 1 



Clypeus entirely yellowish 14 



14. Yellow on dorsulam forming a U, as in Monedulaformosa; sixth 



dorsal segment somewhat wrinkled TJ-scripta. 



Yellow on dorsulum, if present, in the shape of short, parallel 

 lines or spots; sixth dorsal segment punctured 15 



15. Markings of ventral abdominal segments forming broad, non- 

 interrupted bands; eyes strongly diverging beneath. 



oecidentalis. 



Markings, of ventral abdominal segments small, widely inter- 

 rupted, or connected by a narrow apical line 16 



16. Thorax densely pruinose, not spotted on the sides; markings of 

 of abdomen broad, united internally, greenish white . pruinosa. 

 Thorax at the most clothed with a thin, pale pubescence, more 

 or less yellow on the sides 17 



17. Fore coxse and greater part of sides of thorax, black, 



troglodytes. 



Fore coxae and greater part of sides of thorax, yellow .... Sayi. 2 



1 This form of texana, having the middle segment maculated above is 

 unknown to me. 



2 According to Handirsch's description, the dorsulum of troglodytes is 

 spotted medially. The specimens before me do not show this character, differ- 

 ing in that respect from Sayi, which has two central and a posterior yellow spot. 



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