Horn.] — ^'i [.Tune 20, 



the front, ami the chib has no distinct cavity for its lodgment, being 

 merely received in a slight depression on the under side of the thorax in 

 front of the coxie. 



The following are the species known to us : 

 Head with suiira-orbital stria. 



Elytra without an entire stria ; propygidinm smooth at 

 middle ; mentum not carinate ; prosteruum moder- 

 ately prolonged in front but obtuse. 

 First and second striie visible at base only, the second 



short (^Yucateca. 



First and second stria) basal, the second very short, 

 •but Avith an apical ijortion extending forward to the 



end of the first stria 9 /7''«/i(7i<J. 



Elytra with the second stria entire ; mentum with 

 oblique ridge on each side ; prosternal lobe very 

 acute in front ; pygidium and propygidium sub- 

 opaque, the latter sparsely punctured at middle. 

 First elytral stria short, continued by a row of fine 



punctures, second entire cacti. 



Head Avithout supra-oi'bital stria ; prosteruum in front 

 truncate 

 Elytra with one stria entire. 

 Second stria entire, first short, basal. 

 Head without frontal stria ; sides of thorax smooth . quadridentata. 

 Head with sinuous fi'ontal stria sometimes inter- 

 rupted at middle ; sides of prothorax coarsely 



punctured vicina. 



First stria entire, second very short. 



Front not striate, sides of thorax with few punc- 

 tures lucida. 



Elytra without entire striaj, first and second stria; short 

 basal, the latter very short. 



Second stria without apical appendicular stria fossularis. 



Second stria with apical appendix, advancing forward 

 nearly opposite the end of the first populnea. 



H. Yucatecao, Mars. Mon. 1853, p. 203, pi. 5, fig. 1 ; 18G0, p. GOG ; 

 graviJis^ ZMars. 1. c. p. 304, i)l. 5, fig. 2 ; princeps Lee. Proc. Acad. 1859, 

 p. 310. 



Mentum transversely slightly concave, anteriorly triangularly emar- 

 ginate, surface sparsely punctured and without elevated lines. Head 

 with supra-orbital stria and a slight process on each side behind the 

 mandibles. Elytra with two short dorsal strias, the inner very short and 

 without apical appendix to sectmd g , or with apical appendix reaching 

 nearly the tip of the first 9 ; subhumeral deeply impressed extending two- 

 thirds the length of the elytra, Propygidium smooth with fine j^unc- 



