Mar. 1899] Fall : On American Species of Acm-^odera. 9 



in ampliioUis, the apical plate well de\eloped, broad with the free 

 edge thin and subtruncate. Length, 11 ram., .44 inch. 



Habitat : Arizona. 



A single specimen in the Horn collection, evidently allied to 

 ampUcolIis, disjuncta, etc., by the broad depressed form and thoracic 

 characters, but easily distinguished from all by the unspotted thorax, 

 blue-green lustre and maculation of the elytra, which more nearly re- 

 sembles ornata than any of the species with which it is structurally as- 

 sociated. In siihcyanea, as is usual, the punctuation of the thorax in- 

 creases in density from the middle to the lateral margin where it is 

 more or less cribrate, but in those species with yellow marginal stripe 

 it will be observed that the yellow area is generally distinctly less 

 densely punctate than the adjacent surface. 



A. amplicollis Lee, Proc. Acad. Sc. Phil., 1866, p. 383. 



A very easily recognized species, and one which varies but little in 

 coloration judging from the one hundred or more specimens which 

 have come before me. Length, 9-13 mm., .36-. 52 inch. 



Habitat : All specimens seen are from the southern portions of 

 Arizona. 



A. disjuncta, sp. nov. 



Very similar in form, size and markings to amplicollis, from which 

 it differs as follows. The color is black without metallic lustre ; the 

 thorax exceeds the elytra slightly less in width, and is less closely 

 punctate ; the marginal elytral stripe in ainplicollis is here more or less 

 broken, and the discal stripe is replaced by a series of three spots, the 

 posterior sometimes connected with the margin ; the apical fasciae are 

 more broken and are invariably red at the sides. The hairs of the up- 

 per surface, more especially of the thorax, are darker in color. The 

 fifth interspace of the elytra is slightly but distinctly elevated in basal 

 half in amplicollis, not at all so in disjuncta. The under surface is not 

 quite so strongly punctate, and is b ack, not greenish as in amplicollis. 

 Length, 9-12 mm., .36-. 48 inch. 



Habitat: Arizona. 



Described from a series in the Horn collection, the larger of which 

 were placed with amplicollis, and the smaller with opacula. They are 

 perfectly homogeneous and undoubtedly distinct from amplicollis, and 

 have a very different look from the type of opa cuius, though it must 

 be confessed that the status of this latter species is not very well de- 

 fined. 



