Hurn.l «M [Feb. 21, 



Male. First joint of antennae nearly as long as the head, flattened and 

 gradually thicker to tip and sinuate on the anterior margin near the tip; 

 second joint longer than the third and equal to the fourth. Sixth ab- 

 dominal segment feebly emarginate at tip. Antennae at base smooth very 

 sparsely punctured. 



Female. First joint of antennae not flattened, slightly thicker at tip, 

 punctured and pubescent, joints 2-11 sub-equal. Sixth abdominal seg- 

 ment sub-truncate. 



The characters of the table and those above will readily enable this 

 species to be separated from all those which it most closely resembles in 

 general appearance. Abundant in Texas. 



M. longicollis, Lee. Proc. Acad. 1853, p. 343. 



Closely resembles the preceding species and differs superficially in 

 having the antennae and parts of mouth entirely black, the thorax with- 

 out the discal narrow black spaces and the humeral spot longer. It differs 

 especially in its sexual characters. Length .80 — .90 inch ; 20-23 mm. 



Male. Antennae with first joint as long as the head, flattened, very 

 feebly sinuate at anterior margin near the tip, sparsely punctured, joints 

 2 and 3 sub-equal. Abdomen as in albida. Anterior tibiae with one 

 spur. Inferior edge of femora glabrous. 



Female. Antennae with first joint less than half the length of head, 

 slightly flattened, punctured and pubescent, second joint slightly shorter 

 than third and nearly equal to fourth. Anterior tibiae with two spurs. 

 Inferior edge of femora pubescent. Occurs in Texas, Arizona and New 

 Mexico. 



M. atrivittata, Lee. Proc. Acad. 1854, p. 224. 



More elongate than the preceding species and differing in the surface 

 vestiture, as follows : Head pubescent with black, a small white ante- 

 ocular space and median narrow line cinerous. Antennae and parts of 

 mouth black. Thorax cinereo-pubescent with a large black space at 

 middle, divided by fine median cinereous line. Elytra pubescent with 

 black, suture narrowly, apex and sides more broadly cinereo-pubescent, 

 and a moderately broad cinereous vitta extending from the humerus 

 and not attaining the apex. Body beneath cinereo-pubescent, at the 

 sides black, abdomen black apices of segments cinereo-pubescent. Legs 

 black, outer side of femora cinereo-pubescent. Length .70-1.28 inch ; 

 18-32 mm. 



Male. First joint of antennae flattened, broadly dilated at tip and 

 obliquely truncate at tip, longer than the head, shining and sparsely 

 punctured, second joint stout, broader than long and longer than either 

 the third or fourth, third joint small, shorter than the fourth which is 

 also stout and half the length of the fifth ; joints 5-11 robust but elon- 

 gate. Terminal joint of labial palpi disciform. Anterior tibia; with one 

 terminal spur. Sixth abdominal segment broadly emarginate at tip. 

 Inferior edge of femora glabrous. 



