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ENTOMOLOGICAL SOCIETY 



and varieties assigned to this genus, and of related species, and 

 finds it necessary, as a result of these studies, to broaden and 

 give a different basis to the characterization of the genus. The 

 so-called lattice, or more properly tessellated patch, is a char- 

 acter of minor importance, and appears in some degree in al- 

 most all species which have a tendency to develop a strongly 

 chitinized dorsal surface of the pygidium. A much better 

 character found in all the species which have been assigned 

 to this genus is the deep, sharply defined constriction dividing 

 the body into two subequal sections ; and if all the species al- 

 ready assigned to this genus and others having this character 

 are brought together, an assemblage which seems to be justi- 

 fied is formed. 



This character will include in this genus three or four spe- 

 cies which have hitherto in literature, or by the writer at least, 

 been assigned to the genus Targionia, and also articnlatus 

 Morgan, with variety cclastri, the species hitherto referred to 

 the monotypical genus Selenaspidus. Two new species have 

 been added, viz., lounsburyi, closely allied to articulatiis, but 

 lacking the pygidial spur, and greeni, related to trilohitiformis. 



With the exception of articnlatus and allies, all of the species 

 now assigned to Pseudaonidia show more or less of a dorsal 



Fig. 8. — Pseudaonidia articulatus: a, Adult female, greatly enlarged; b, anal 

 segment of same, more enlarged; c, tip of anal segment of same, still more en- 

 larged, (Drawings made in the Bureau of Entomology and published by per- 

 mission of the Secretary of Agriculture.) 



chitinization of the pygidium, and in the case of most of them 

 this chitinization takes the form of the so-called lattice patch. 

 In curcnUginis Green, which is in general closely related to 



