MEXICAN FORMICID^. 



BY THEO. PERGANDE. 



The present paper is based upon a collection of Form- 

 icidcC, made by Messrs. Eisen and Vaslit during Septem- 

 ber, 1894, ^^ ^^^ Cape Region of Lower California and 

 during October and November on the mainland of Mex- 

 ico; the majority having been taken in the territory of 

 Tepic, and on an overland trip from the city of Tepic to 

 Mazatlan, all on the Pacific Coast of Mexico. 



In addition to a few species which have been previously 

 recorded by me, the collection contains quite a number 

 of new or otherwise interesting forms, some of which 

 have not heretofore been observed to occur so far north, 

 while a few extend their territory into Texas and even as 

 far east as Missouri. 



Subfamily Camponotini. 



I. Brachymyrmex admotus Mayr. 



Brachymyrmex admotus Mayr., Verb. zool. bot. Ges. Wieu, xxxvii, 

 1887, p. 523. 



Worker: Length, 1.6 mm. Head somewhat longer 

 than broad, its sides nearly parallel and slightly arcuate; 

 the occiput emarginate. Clypeus broader than long, 

 strongly convex, arcuate in front. Scape, reaching be- 

 yond the occiput. Ocelli very minute. Mandibles nar- 

 row and furnished with four acute teeth ; their surface 

 polished, indistinctly striated and sparsely punctured. 

 Thorax not much longer than the head, stout, of nearly 

 equal width; the prothorax about one -fourth narrower 

 than the head; constriction between the meso- and meta- 

 notum rather deep, the declivity of the metanotum flat 

 and longer than the basal section. Scale small, narrow, 

 rounded at apex. Entire surface of body polished, the 

 thorax and abdomen with extremely fine and transverse 



2d Ser., Vol. V. December 30, 1895. 



