66 THE CANADIAN ENTOMOLOGIST. 



long. The cauda is very long and stout for the size of the louse ; the 

 cornicles are stout, strongly tapering towards tip and without distinct 

 flange ; 3rd joint of antenna with about 15 to 20 circular sensoria, varying 

 much in size ; joint 4 without sensoria ; a few stout hairs on joints i 

 to 5 ; frontal tubercles rather prominent, converging towards the head, 

 but widely separated. Thorax without lateral tubercles, or with very 

 small ones. 



The nymphs are dark amber in general colour. 

 Aiate Viviparous Female. — Taken from chrysanthemums at Fort Collins, 

 December 12, 1907. 



General colour black, shining, with more or less of brown amber 

 colour on posterior margins of the abdomen and in the region of the 

 cornicles ; coxae and distal ends of femora and tibiae very black ; proximal 

 ends of femora and tibiae of a light amber colour. 



Length of body, 1.43 mm.; antenna, 2 mm.; wings, 2.90 mm ; cor- 

 nicles, .20, and Cauda, .23 mm. Joints of antenna : III .60, IV .26, 

 V .30, VI .13, VII .54 mm. Joint 3 is strongly tuberculate, with a large 

 number of sensoria. Joint 4 has about ten sensoria similar to those of 

 joint 3 ; joint 5 has a single sensorium at distal end ; joints set with 

 numerous rather strong hairs. 



For a fuller description of the alate female see paper on Kansas 

 Aphididce, in Vol. Ill, No. i, Kansas University Science Bulletin, by C. 

 E. Sanborn. 



Prof. Sanborn, supposing he had before him Oestlund's Nedarophora 

 chrysa?ith€?}ii (quite a different species), described the alate female of this 

 common chrysanthemum louse. 



It is possible that this louse is the one called by Williams Siphonophora 

 chrysantheviicokfis in Mx^ Host- plant List of North American Aphididce, 

 Special Bulletin I., Department of Entomology, University of Nebraska, 

 1891, but without one word of description. In all probability it is what Mr. 

 Gahon has referred to in Bulletin 119 of the Maryland Exp. Sta., p. 14, 

 as the " Black Aphis of the Chrysanthemum," but also without descrip- 

 tion. I believe it entirely wrong to accept a name proposed as chry- 

 safithemicolens was. If there is any group of insects more than another 

 that need a very careful characterization to establish the identity of the 

 species, it seems to me that it must be the Aphididae. 



