NORTH AMERICAN COLEOPTERA. 



185 



The smoother specimens are from Arizona, the deeply wrinkled from 

 New Mexico. 



M[. gigas Lee. — Black, shining. Front sparsely finely punctate. Scape of 

 antennae smooth, the fourth joint alone broadly annulate. Thorax as wide as 

 long, slightly narrower in front, the sides with a long acute spine directed upwards 

 and slightly backward, surface with few punctures, more numerous along the basal 

 margin. Elytra oval, somewhat narrower behind, humeri oblique, disc slightly 

 flattened, sides obtusely margined and abruptly declivous, the surface with coarse 

 punctures extending two-thirds to apex. Body l)eneath smooth, shining, femora 

 smooth. Length 1.20-1.36 inch: 30-34 mm. 



The first three joints of the anterior and middle tarsi are spongy pu- 

 l>escent beneath with narrow median line. The first joint of the hind 

 tarsus is not pubescent, the second with a small space on each side spongy 

 ]Hibescent, the third entirely so. 



The specimen before me, the type of the description of Dr. LeConte, 

 has the coarse punctures of the elyti-a rather regularly disposed over the 

 entire surface two-thirds to apex and on the sides to the same extent. 

 Two other specimens have the middle of the disc of the elytra almost 

 entirely free of punctures, these being placed near the side and on the 

 deflexed portion. In both forms the side of the thorax below the spine 

 is coarsely punctured and the median line of the disc slightly impressed 

 posteriorly. 



Occurs in Arizona. 



j^I. seniipunctatum Lee. — Form rather elongate, black, shining. Front 

 punctured with coarse and fine punctures intermixed. Scape of antennae sparsely 

 punctate, the other joints not annulate. Thorax a little wider than long, sides 

 slightly arcuate with a small subacute spine, the surface puaetured over the entire 

 disc with coarse and fine punctures intermixed, the sides below the spine coarsely 

 punctured. Elytra oval, more than twice as long as wide, slightly narrower pos- 

 teriorly, sides abruptly deflexed, an obtuse margin near the humeri, the surface 

 sparsely punctured, the punctures gradually finer and these wanting on the apical 

 third, the sides with more numerous punctures near the base, then sparser two- 

 thirds to apex. Body beneath sparsely finely punctate, femora punctate. Length 

 .74-1.00 inch; 18.5-25 mm. 



The tarsi beneath are as in gigas. The only variation observed is that 

 usual in all the species, consisting of a greater or less distinctness of the 

 punctuation. This species and subrugosum are the only ones in which 

 the scape and the femora are observed to be punctate, this is however 

 much less distinct here than in that species. 

 Occurs at Cape San Lucas, Lower California. 



M. Isevigatuni Bid.— Moderately elongate, black and very shining. Front, 

 sparsely punctate each side. Scape of antennse smooth, joints 3-6 indistinctly 

 annulate. Thorax slightly wider than long, sides feebly arcuate, a small acute 



