8 GEO. H. HORN, M. D. 



NAXIXI^i Lac. 

 The species of this genus at present known to inhabit our ftiuna 

 may be separated in the following manner : 



Elytra with hotli humeral and apical red spots. 

 Thorax distinctly punctate; punctures of the rows not confused near the 



scutellum apicalis. 



Elytra witli humeral spot alone. 



Humeral spot large, involving tLe entire epipleural lobe, extending rather 

 more than a third from the humerus toward the apex. 

 Punctures of thorax rather coarse and close, particularly deep near the side 

 margin ; elytral sculpture rather rough ; surface somewhat dull. 



sonoreiij^is. 

 Punctures of thorax neither coarse nor clo.se, a little coarser near the sides, 

 but not den.se; rows of punctures of elytra well defined: surface mod- 

 erately shining Oiiiogera. 



Humeral spot umbonal, not involving the half of the epipleural lobe; thorax 

 comparatively smooth. 

 Elytra rather closely punctate, the punctures of the striae irregular and con- 

 fused with those of the intervals; surface rather dull SRllcia.. 



Elytra with the punctures of the strise fine and not closely placed, those of 



the intervals few and very fine, surface quite smooth politlila. 



Elytra without humeral red spot. 



Thorax sparsely finely punctate; punctures of elytral rows distinct, but ir- 

 regular; surface rather dull speciilifera. 



As a general rule the Chrysoraelidae are noted for their variability 

 in ornamentation, but in the present genus, as far as our representa- 

 tion shows, the spots are constant as to form and extent, so that I can 

 use then) as a means of separating species in tabular form. 



S. apicalis Lee, Trans. Am. Ent. Soc. xii, 1884, p. 25 — Eather more elon- 

 gate than our other species, blackish blue, the thorax somewhat greenish. Head 

 rather coarsely punctate. Thorax sparsely, finely punctate on the disc, a little 

 more coarsely and closely on the declivity. Elytra striato-punctate, the punc- 

 tures moderately coarse, but not crowded, becoming finer toward the apex, all 

 the rows are regular, even the scutellar is not confused, intervals with sparsely 

 placed finer punctures; humeral red spot large, extending inward to the second 

 stria, involving the entire epipleural lobe, apical spot round, not reaching either 

 the suture or apex; epipleural lobe subangulate; body beneath densely finely 

 punctulate and clothed with fine cinereous pubescence. Length .24 inch. ; 6 mm. 



Differs from all our species by the presence of a sub-apical red 

 spot in addition to the humeral and by the sub-angulate epipleural 

 lobe. In the latter respect it seems allied to the Mexican saginata. 

 It is the only species in our fauna with all the rows of punctures 

 distinct. 



Occurs in southern Arizona (Morrison). 



