MASTOSTETHUS. 21 



convex in the present species, while it is concave in M. bicolor. The extreme apex of 

 the tibiae and all the tarsi are black. 



8. Mastostethus salvini. (Tab. I. fig. 18.) 



Mastostethus salvini, Jacoby, P. Z. S. 1878, p. 983. 

 Hab. Costa Rica, Cache (Bogers). 



Testaceous, sides of the breast and the upper part of the head shining black ; thorax rufous ; elytra light 

 testaceous, a large semiquadrate patch from the base to the middle of each elytron, and a broad trans- 

 verse fascia behind the middle, common to both elytra, black. 



Length 4| lines. 



The pattern of the elytra in this species is different from that of any other known 

 to me, the black portion being divided by a narrow triangle of testaceous, two arms 

 of which extend across the disk, the other along the suture to the base. 



9. Mastostethus sexplagiatus. (Tab. I. fig. 24.) 



Mastostethus sexplagiatus, Lacord. Mon. p. 658 \ 



Hab. Mexico 1 ; Guatemala, Zapote (Champion). 



Specimens from the last locality belong to var. B of Lacordaire, the thorax being 

 entirely black or narrowly margined with testaceous. 



10. Mastostethus rubricollis. (Tab. I. fig. 20.) 



Mastostethus rubricollis, Chevr. Col. Mex. cent. i. 1834 ; Lacord. Mon. p. 659. 

 Hab. Mexico. 



To Lacordaire's description I may add that the black transverse band across the disk 

 of the elytra is nearly straight, and not oblique, as in the preceding species, while it 

 is connected with the black apex by a narrow line of the same colour at the lateral 

 margin. 



11. Mastostethus championi. (Tab. II. fig. 12.) 



Elongate, parallel, testaceous ; head and thorax fulvous ; antennae, tibiae, and tarsi black ; elytra pale 

 testaceous, a transverse narrow band at the base, another broader one behind the middle and the apex, 

 black. 



Length 4^ lines. 



Head closely and rather deeply punctate near the inner margination of the eyes, more distantly at the vertex ; 

 apex of the mandibulse black ; thorax of usual shape, the posterior margin nearly straight, surface with 

 an oblique short groove on each side near the anterior and posterior margins, fulvous, covered with very 

 distinct but remotely-placed punctures ; middle of the disk with a more or less distinct black spot ; seu- 

 tellum fulvous ; elytra parallel, rather deeply and closely punctate at their anterior half, finer and more 

 distantly towards the apex, of a light testaceous colour with a transverse black band at the base not 

 quite touching the lateral margin and slightly narrowed towards the suture ; another broader band is 

 placed behind the middle, and, extending to the apex along the sutural and lateral margin, surrounds two 

 oval spots of the ground-colour ; underside and legs light fulvous ; tibiae and tarsi black. 



