NORTH AMKRICAN COLEOPTERA. 85 



a distinct intercoxal cariua. Metastenuim smooth. Abdonu'ii coarsely punctate 

 at sides, smooth at middle, the segments crenate in front. Anterior tibite triden- 

 tate externally, crenate above. Posterior femur smooth, the marginal line ab- 

 sent, except a faint trace near the knee, posterior tibia with accessory spinule, 

 the first tarsal joint as long as the long spur. Length .18 inch; 4.5 nun. 



As will be seen by the characters of the table this species is most 

 nearly allied to cognatus, and is the only one about which there 

 should be any difficulty. On comparing the two the punctuation of 

 the present is strikingly coarser on the thorax and the fine jjunctures 

 extremely minute. In cognatus the intervals (jf the elytra are dis- 

 tinctly crenate on both sides. 



Occurs at 8an Bernardino, Cal. 



A. lobatus Horn. — Oblong oval, slightly broader behind, moderately con- 

 vex, piceous brown, shining; legs reddish brown. Antennse rufotestaceous. 

 Head moderately convex, coarsely punctured along the occiput, at middle more 

 sparsely finely punctate, at sides and front transversely wrinkled. Clypeus im- 

 pressed in front, broadly emarginate at middle, the angles broadly rounded, sides 

 slightly arcuate, gense moderately prominent, obtuse. Thorax nearly twice as 

 wide as long, not narrowed behind, sides feebly arcuate, hind angles very obtuse, 

 base strongly arcuate, the marginal line di.stinct, disc moderately convex, with 

 coarse and deep punctures rather .sparsely placed along the base and at the sides 

 with finer punctures intermixed, the middle and anterior portion of disc with 

 very few coarse punctures and with fine punctures sparsely placed. Elytra as 

 wide at base as the thorax, slightly broader behind, base arcuately emarginate, 

 humeri dentate, disc deeply striate, strife not closely punctured, intervals mod- 

 erately convex and with few very fine punctures, the inner side finely crenate. 

 Mesosternum densely punctured and opaque, carinate between the cox»e. Meta- 

 sternum smooth. Abdomen with few obsolete coarse punctures at the sides, 

 smooth at middle. Anterior tibise tridentate externally, crenate above. Poste- 

 rior femur smooth, except a few large punctures near the knee, the marginal 

 line fine, extending one-third toward base, the tibia with distinct accessory 

 spinule, the first tarsal joint as long as the long spur. Length .22 inch ; 5.5 mm. 



This species has a more robust facies, is broader behind and more 

 convex than any of the series to which it has closest relationship. 

 The color is always ])iceous brown or dark castaneous but never 

 l)iceous-black. While the thorax is more coarsely i>unctured than 

 in cogmitus it is less so than in californicu.s. The thorax is also more 

 arcuate at base, and the base of the elytra correspondingly emar- 

 ginate, while in the preceding species the elytral base is truncate. 



While all the forms from iiiqumfus to the present species are closely 

 allied and difficult to separate by description, they .seem quite dis- 

 tinct and readily separable when the specimens are seen. 



Occurs at Cape San Lucas, Lower California. 



