Figures 37—56 



37-54. Eighth sternites of male genitaUa, ventral aspect, all drawn to the 

 same scale from males with wingspread of 25-27 mm., except figures 52-54 

 (52 was 31 mm., 53 was 28 mm., 54 was 21 mm.). Note the distinctive shape 

 and/or size of disstria, constridum constrictum, tigris, and americanum, and the 

 minor variations on a single basic shape shown by incurvum (figs. 41-43) and 

 calijornicum (figs. 44-51). Variations as great as these may be found within a 

 subspecies, so the eighth sternite (and other genitalic structures) cannot be 

 used for identification of infraspecific taxa. See also figures 12-29 and 57-74 

 for a comparison of other genitalic structures from the same specimens. 



37. M. disstria. 



38. M. constrictum cotistrictum. 



39. M. tigris. 



40. M. americanum. 



41. M. incurvum incurvum. 



42. M. incurvum discoloratum. 



43. M. incurvum aztecum. 



44. M. calijornicum calijornicum. 



45. M. calijornicum ambisimile. 



46. M. calijornicum recenseo. 



47. M. calijornicum pluviale, Seattle, Washington. 



48. M. calijornicum pluviale, Alberta (bog population). 



49. M. calijornicum lutescens, Saskatchewan. 



50. M. calijornicum lutescens, Oklahoma. 



51. M. calijornicum Jragile. 



52. M. neustrium. 



53. A/, castrensis. 



54. M. Jranconicum . 



Note the greater similarity of Jranconicum to castrensis than to neustrium (except 

 for size). 



55. Median antennal segments of female neustrium. 



56. Median antennal segments of female castrensis. Female Jranconicum are 

 similar. 



214 



