64 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 121 



still larger and darker and constituted the subspecies franciscanus. 

 This suggests a north-south cline from southern California and east- 

 west cline through central California. Our studies show a sharp break 

 between the populations along a line in the Tehachapi Mountains, 

 California, and if there is a north-south chne, it is abrupt and not 

 gradual as outlined by Van Dyke. On the average, specunens from 

 the mountains are smaller and those in the lowlands larger. (Although 

 one of the smallest specimens of oregonensis in our material is from 

 Pleasanton, Alameda Co., Calif.) This is most hkely a phenotypic 

 expression of a more vigorous clunate, shorter simimer season, and 

 perhaps less abundant food in the mountains, and we think has nothing 

 to do with the genotypic characters which distinguish the two sub- 

 species. The form franciscanus is regarded as merely a larger^ and 

 darker phenotype of oregonensis that enjoys a more favorable environ- 

 ment but does not warrant nomenclatorial recognition. 



The species variolatus has been synonjnnized with longulus by Van 

 Dyke (1932) on the grounds that it was based on individual variants 

 and in this we concur. 



41. Melanotus gradatiis LeConte 



Figure 7g; Plate Ip 

 Melanotus gradatus LeConte, 1866, p. 390.-Blatchley, 1910, p. 753.-Thomas, 

 1941, p. 260. 

 Male.— Body color reddish brown, covered with white or yellowish 

 vestiture that grows denser and sometimes nearly velvety posteriorly 



on pronotum. 



Head: Front with pair of shallow anterolateral depressions; margm 

 not strongly protuberant above nasale, evenly rounded or flattened 

 in front when viewed from above; parantennal fovea moderately large, 

 deep, semicircidar, foveal tragus smaU; nasale raised slightly, width 

 from' 1% to IK times height. Mandible with large teardrop-shaped 

 pit. Antenna reddish brown, exceeds tip of hind angle by one-half 

 segment or less, segment 3 nearly as large as 4, 4 about lYi times as 

 long as maxunum width; erect male hairs very short, fine, rather 

 sparse, and easily overlooked. 



Pronotiun about as wide as long; punctures on anterior two-thirds 

 as large as those on front, and separated by distance equal to less 

 than own diameter, those on posterior one-third grow much smaller 

 and denser, often giving surface granulose appearance; sides of pro- 

 notum vary from straight and diverging posteriorly to curved with 

 slight concavity at base of hind angle; hind angles divergent, carina 

 usuaUy extending cephalad of base of hind angle and weakened 

 anteriorly. Genitalia as figured; paramere with apical blade. 



Elytron: 7.9-8.2 mm. 3 spec. 



