160 MEMOIRS ON THE COLEOPTERA 



laterally, in the much more closely punctulate and pubescent 

 propygidium and less transverse and more convex pygidium; the 

 hind tarsi are evidently shorter. There are only two brown 

 pronotal spots at each side of the median, anteriorly flavomaculate 

 vitta, not counting the constant sublateral dark dot. The true 

 home of lunulata is Brazil, though there are some closely allied 

 forms in Mexico and other regions, of which oblita is one. 



Dichromina n. gen. 



There are two structural characters common to all the species of 

 the dimidiata type, which constitute it one of the more distinct 

 and specialized divisions of the great Cyclocephala complex, and 

 without doubt it is therefore entitled to generic distinction. These 

 structural features refer to the form of the larger claw of the anterior 

 male tarsi and to the very small, indeed relatively minute, tarsi. 

 The general habitus, due to the peculiar form and coloration of the 

 body, is also rather distinctive though practically reproduced in 

 the next genus, as well as in Cyclocephala atricapilla, which is here 

 referred to the genus Stigmalia, though probably not truly belonging 

 there ; if we overlook the large head and very peculiar pygidium of 

 atricapilla, it could just as well be placed in Homochromina; in 

 pygidial structure of the female, it however does not accord with 

 any known generic type. Guttata Bates, seems to belong to this 

 genus, although my single example is a female, as was also the 

 unique type described in the Biologia; besides this and a species 

 probably from Brazil, though marked "Peru" on the label, sent 

 to me under the name melanocephala Fabr., there are in my collec- 

 tion the four following species: 



Eyes separated by twice their width or more in both sexes 2 



Eyes notably large and prominent, separated by less than twice their 



width in both sexes 4 



2 Pygidium (9) shining, with well separated, shallow, irregular punc- 

 tures throughout; prothorax shorter, nearly twice as wide as long. 

 Body elongate-oval, moderately convex, shining, pale red-brown in 

 color, the sterna sometimes black, the elytra pale brownish-flavate; 

 head about half as wide as the prothorax, black, discretely and 

 irregularly punctate; clypeus rufous to nearly black, two-fifths wider 

 than long, trapezoidal, very coarsely but shallowly rugose, convex, 

 broadly impressed along the middle, the truncate apex moderately 

 refiexed and smooth, the obtuse angles not rounded; antennal club 

 small, oval, barely more than twice as long as wide; clypeal suture 



