284 



REVISION" OF THE TENEBRIONID/E OF AMERICA, 



A. m orb ill os a, (Peleoyph.) Lee, Proo. Acad. 1858, p. 71. 

 Plulolithus id., Lac. Genres. Vol. V., p. 725. 



Resembles the preceding. The humeri of the elytra arc toothed. The thorax is 

 truncate behind with rectangular angles. The elytra, are sculptured as in the preceding. 

 The costa does not, however, end in a spine. Some specimens from Lower California 

 differ from this type in the form of the thorax, being less convex along the middle and 

 more nearly resembling the outline of cegrota. Tbe humeral angles are dentiform as in 

 moi'billosa. I do not feel warranted in describing it as distinct, but think it points to a 

 union of cegrota and moi'billosa, and when the desert regions of the California peninsula 

 shall have been more thoroughly explored, intermediate forms will doubtless be found. 



Length .75 inch. 



A. aotuosa, black opaque, head opaque, finely granulate; thorax quadrate, broader than long, sides moder- 

 ately rounded, margin finely orenulate, anteriorly emarginate, angles acute, posteriorly nearly truncate, angles rec- 

 tangular, above coarsely punctured along the margin, finely granulate on the disc. Elytra rounded, ova,], very convex 

 above, opaque finely and sparsely granulate, humeri denticulate, sides margined, disc with one costa near the middle 

 of each elytron, concave externally and extending two-thirds the length of elytra, frequently with another obsolete 

 costa within and between it and the suture. Beneath opaque finely punctured. Length .58-.02 inch. 



From Owens' Valley, California. Collected by myself and Dr. Cronkhite. 



This species, like all the others of the genus, is variable. In females or those much 

 inflated, the denticulation of the humeri of elytra is lost. Others collected at Fort Tejon, 

 have perfectly smooth and shining elytra, though preserving the characteristic costa 1 , and 

 losing the opacity as well as the granules of the elytra. Those collected by myself in 

 Owens' Valley were found in the Winter months, while the weather was very cold. 

 Those of Tejon arc Summer specimens, and the weather excessively warm. Until re- 

 cently, I have considered both varieties as distinct species. 



A. Bern Use vis, black opaque, elongate oval. ITcad coarsely and sparsely punctured. Thorax sub-quadrate, 

 moderately convex, coarsely, sparsely and unevenly punctured, sides moderately rounded, posteriorly feebly sinuate, 

 anteriorly emarginate, angles not prominent, base truncate, angles rectangular. Elytra elongate oval, convex, with a 

 distinct; marginal costa, base truncate, angles distinct, disc with six parallel moderately elevated costie, surface between 

 suture and first costa shining, between first costa and margin opaque. Beneath opaque, coarsely and sparsely punc- 

 tured. Length .90 inch. 



Collected by Mr. Win. M. Gabb, in western Nevada. The arrangement of the costse 

 of this species is very peculiar. They are moderately elevated, perfectly parallel to the 

 suture and extend three-fourths of the length of the elytra. The first costa arises from 

 the base slightly within the angles of the thorax; the second on a line of the humeri of 

 the elytra, but at some little distance from it ; tbe third arises from the marginal costa at 

 about one-fifth from the humeral angle. This species commences 'the divergence from the 

 robust form resembling somewhat that of conjluem (infra). 



