444 BULLETIN (y'.i, UNITED STATES NATIONAL MUSEUM. 



found. Its presence about Sacramento and San Francisco Bay can 

 undoubtedly be explained by carriage by the rivers that drain the 

 western slopes of the mountains. Its area of distribution no doubt 

 naturall}" overlaps that of marginata, the latter being a more or less 

 maritime form. Specimens of scahricnla indigenous to the valley 

 Tegions are smaller and with greater difficulty separated from mar- 

 ginata. 



The female genital characters are distinctive, those of the male are 

 not. 



^ A male example recently loaned to me by Mr. A. Koebele, presents 

 varietal characteristics as follows: Form as usual; distinctly depressed 

 on the elytra and pronotum, the latter distinctly sinuate before the 

 basal angles, where the sides are parallel for a short distance; elytra 

 densely, asperately muricato-tuberculate, base transverse and tlie 

 humeri rather prominent and obtusely rounded, sides subparallel 

 nearly as in producta. The protibise are suddenly and distinctly con- 

 stricted at base as in Emhaphion; this character is also observed in 

 planipeMtiis. 



This form may be known as scabricula forma deplanata. 



Habitat. — Napa County, California. 



This specimen surely forms a connecting link betwen sfahrievla 

 and planipennis. On the other hand it may be an aberration, and it 

 remains for other examples to settle this question. 



General ohaeriHitions. — The mentuni has the middle lobe large and 

 variable, usually rounded anteriorly from the middle; frequently 

 subtrapezoidal and subtruncate anteriorly, even slightly emarginate 

 at apex; surface may be feebly convex and simply punctate or more 

 or less foveate laterally. The lateral lobes are very rudimentary. 



The anterior margin of the prosternum is usually more or less 

 stoutly deflexed ; between the coxa^ usually strongly arcuate and more 

 or less vertically declivous posteriorly and not in the least mucronate. 

 The surface may gradually slope downward and backward from the 

 anterior nuirgin to between the coxa*, with which it is quite j)roniinent 

 ventrally. but less suddenly so than in planipennis. The prosternum 

 is frequently strongly grooved betAveen the coxa>. 



In a specimen from IMunuis County there is a small but well marked 

 mucro present. In some specimens from Tulare County (Colony 

 Mills) the ])Osterior nuirgin is feebly comjiressed and quite vertical 

 with a feeble attcMupt at a mucronate angle. The mesosternum is 

 arcuately declivous and more or less concave. 



The metasternum laterally between the coxa» is very short, about 

 equal in length to the width of a mesotibia at apex. 



The abdominal intercoxal process is subquadrate and slightly 

 transverse; its width is equal to the length of the third abdominal 

 segment; the post-coxal portion of the first segment equal to the 



