NORTH AMERICAN COLEOPTERA. 109 



This species should be placed in the division of the genus near im- 

 macnlatn. It resembles linearis somewhat at first sis;ht. 



Collected in x\rizona by Morrison. 



M. suhlineata Lee. has been found to be a rubbed specimen of longi- 

 collis Lee. 



At the time of my review of the species of Macrobasis (Proc. Am. 

 Philos. Soc. 1873) the males of several were wanting to enable me to 

 complete the work. Since that time three new species have been col- 

 lected in our fauna, and additional material of most of the older ones 

 obtained The male of linearis is now known, that of tenella has not 

 yet been found, but I have no hesitation in giving it a place in a tabular 

 arrangement. 



]fl. linearis Lee. — Piceous, elytra and legs in part luteous, rather sparsely 

 clothed with cinereous pubescence. Varies with the legs nearly piceous. 



Male. — Antennae with the first joint long, equal to the next five joints together, 

 scarcely arcuate, the anterior edge with a broad shallow groove ; second joint one- 

 third the length of the first and as long as the next two together; joints 3-11 very 

 gradually shorter and more slender to tip. Anterior tibiae with one terminal spur. 

 First joint of anterior tarsi much shorter than the second, oval, concave on its 

 inner side. Last ventral segment feebly emarginate. 



Female. — First joint of antennae about equal to the next two, joints 2-11 very 

 gradually decreasing in length and more slender to tip. Anterior tibiae with two 

 spurs,. first joint of tarsus long, nearly equal to the next two. 



The following table is the result of a renewed study, and is a modifica- 

 tion of that given by me in 1873. The characters used are entirely 

 sexual, all attempts to prepare an empirical table for the separation of 

 specimens regardless of sex have entirely failed. 



M. Borrei Duges is the only species described out of our fauna, and 

 is added for comparison. 



The accumulation of species indicates that the feeble characters sepa- 

 rating Macrobasis and Epicauta will soon cease to have generic value. 



First joint of antennae dissimilar in the sexes, that of the male being at least as 



as long as the next two and often as long as the next four 2. 



First joint of antennas similar in the sexes, and not in either sex longer than the 



next two 10- 



2. — First joint of antennae % with a sinuation, of varying extent, on the lower 



edge near the tip 3. 



First joint of antennae % without sinuation, straight or feebly arcuate 8. 



3. — Anterior tibiae %, with two terminal spurs 4. 



Anterior tibiae '^ with one terminal spur 5- 



4. — Species large (24 mm.), antennae in part rufo-testaceous ; pubescence fine and 



silken albida. 



Species small (10 mm.), antennae black, pubescence coarse Borrei. 



