232 GEO. H. HORN, M. D. 



which is, however, said to occur in Disonycha, but is not present in 

 any of our species. The posterior edge of the hind tibice is scarcely 

 at all sulcate as in the majority of our Halticje. The genera are, 

 how^ever, so lacking in sharpness of definition in Halticini that in 

 certain cases the position (jf species is purely opinionative, and this 

 is one of them. 



Occurs from Massachusetts to Illinois, Florida and Texas, extend- 

 ing through Mexico to South America. 



Group IX. -LACTIC^. 



Antennte 11-jointed. Thorax with a deep ante-basal groove dis- 

 tinctly limited at its ends usually by being bent abruptly toward the 

 base. Anterior coxal cavities open behind. 



These few characters define the tribe, while it otherwise shows con- 

 siderable variation in its generic membership. The following genera 

 are known in our fauna : 



Elytra nearly smooth, tbe punctuation when present extremely fine and scat- 

 tered L.actica. 



Elytra coarsely striato-punctate. 



Form oval ; without erect hairs Dipliaulaca. 



Form oblong, parallel ; elytra with short hairs arising from interstitial punc- 

 tures Triclialtica. 



These genera belong to the Asiatic region of our fauna. 



L.ACTICA Erichs. 



Head subti-iangular, inserted in the thorax as far as the eyes, these 

 oval, slightly emarginate in front, coarsely granulate. Front broadly, 

 obtusely carinate, the tubercles feeble. Labrum transverse, slightly 

 arcuate in front. Maxillary palpi stout, terminal joint acutely 

 conical, shorter than the preceding, which is as broad at apex as 

 long. Antenm^ longer than half the body, slender, third joint 

 shorter than fourth, joints 4-10 equal, eleventh very little longer. 

 Thorax transverse, with a deep, transverse, ante-basal impression 

 bent at each end rectangularly to the base, apical margin truncate, 

 base arcuate. Elytra oval, scarcely wider at base than the thorax, 

 the punctuation in our species extremely fine and confused. Proster- 

 num separating the coxte and slightly prolonged, the cavities open 

 posteriorly. Metasternum oblique. Legs rather slender, the ante- 

 rior and middle tibise bisulcate externally, posterior tibiae with a 

 short sulcus at apex and a row of cilice on the outer side extending 



