20 PROCEEDINGS OF THE NATIONAL MUSEUM vol.82 



median basal depression; finely alutaceous and finely punctate; a 

 broad dark band extending across pronotum leaving only the margin 

 pale. Sciitellum dark. Elytra narrowly oblong oval, humeri marked 

 b}' a short intrahumeral sulcus; surface alutaceous and distinctly 

 and quite densely punctate; dark sutural, median, and submarginal 

 vittae, these not vi^ider than pale intervening vittae; the median 

 dark vitta frequently narrow, interrupted, or, even vanishing; sutural 

 and submarginal vittae not uniting at apex. Body beneath finely 

 pubescent, entirely dark, legs dark. Length, 6 to 8 mm ; width, 2.5 to 

 3.8 mm. 



Type locality. — Sacramento, Calif. 



Distribution. — California (Lake County, Los Angeles, Los Gatos, 

 Moorland, San Joaquin County, Santa Clara County, Stockton) ; 

 Nevada (Elko). 



Food plant . — Polygonum sp. 



Remarks. — LeConte described this as similar to but narrower than 

 pcnsylvanica (probably meaning uniguttafa), and with the thorax 

 sparsely punctured, the elytra not sulcate, and the yellow vittae 

 broader. In the LeConte collection are four specimens bearing the 

 gilt label indicating their locality as California, one of which is 

 labeled limbicoUis, and all of which fit LeConte's description. The 

 chief points of difference between liinbicollis and uniguttafa appear 

 to be in the generally somewhat narrower shape of linibicollis, its 

 uniformly darker head and undersurface, and its slightly narrower 

 elytral vittae, the median one of which is often interrupted or 

 evanescent. The aedeagus is also slightly dift'erent. D. limbicollis 

 may be only a dark variety of uniguttata, but because of its geo- 

 graphic isolation west of the Rocky Mountains, and the fact that 

 imiguttata does not seem to be found beyond the Great Plains, it 

 may best be regarded as a distinct species. 



6. DISONYCHA ALTERNATA (Illiger) 

 Plate 2, Figure 8 



Ealtica altemata Illigek, Mag. fiir Insekt., vol. 6, p. 144, 1807 (Carolina and 



Pennsylvania; type in Berlin University Zoological Museum). 

 ? Altica qmnqucinttata Say, Journ. Acad. Nat. Sci. Philadelpliia, vol. 4, p. 88, 



1824 (Missouri; type lost). 

 Dhmiycha altemata Stxjem, Catalogue, p. 283, 1843. — Ceotch, Proc. Acad. Nat. 



Sci. Philadelphia, vol. 25, p. 64, 1873. 

 Disoni/cha quinqtievittata Houn, Trans. Amer. Ent. Soc, vol. 16, p. 203, 1889 (in 



part). 

 Disonyclia quinquevittata var. pmwtigera ScHAEffFEB, Jouru. New York Ent. 



Soc, vol. 39, p. 279, 1931. (Not D. punctigera LeConte.) 



Description. — Broadly oblong oval, moderately shining; pale, head 

 with labrum, occiput, and usually tubercles brown; pronotum usually 

 5-spotted, sometimes only 2-spotted, elytra with narrow sutural, 



