HETEROGYNA — MYRMICIDiE. 103 



Antennaj 13-,joiiite(l, first joint of funicle not ijlolxise, scaj)e clonjrate 

 clavate ; marginal cell closed at apex; mesothorax with converjjinfi 



impre.ssed lines Sfeiiaiiiiiiii Westw. 



Marsjinal cell remarkably short, hroadiv ronnded apically, slijima larfre, 

 thick, short; antennie l'i-13-jointed, scajje eloii<;ate, about as long as 

 the first three joiifts of funicle united; mesothorax with converging 



impressed lines IvOptotliora.v Mayr. 



7. — Wings dark colored, pilose, ciliated, marginal cell short, obtuse at tip, appen- 

 diculate; antennae 13-jointed, first joint of funicle cylindrical ; man- 

 dibles rather narrow, trideutate, concealed beneath the labrum ; 

 mesothorax with two convergent grooves; metathorax bidentate. 



Myrmecina Curtis. 

 Wings hyaline, not pilose or ciliated, marginal cell long, pointed at tip; an- 

 tennae 12-13-jointed, usually attenuate ; mesothorax without convergent 

 grooves; metathorax usually unarmed iVIouoiUOi'iuiil Mayr. 



Note. — Since the above was in type, the compiler has seen a copy of Dr. Mayr's 

 recent paper, entitled " Die Formiciden der Vereinigten Staaten von Nordamerika 

 (Verb, zool.-bot. Ges. Wien, Dec. 1886), in which the following genera, not char- 

 acterized in the foregoing tables, are mentioned as occurring in our fauna. 



Dr. Mayr appears also to have confirmed his former opinion that Labidus is the 

 % of EcitoH. 



Irifloiuyrinex Mayr. — ^ . Head, together with the mandibles, triangular, 

 being narrowed toward the cheeks; mandibles very broad, the apical (or l)iting) 

 margin only slightly shorter than the exterior margin, more or less distinctly 

 toothed; maxillary palpi 6 jointed, short; middle lobe of labrum broadly trian- 

 gular, deeply emarginate medially, lateral lol)es pointed; clypens triangular, the 

 posterior angles strongly rounded, not carinate, only moderately convex ; clypeal 

 foveffi uniting with the antennal fovese ; frontal carina arising at the lateral mar- 

 gin of the clypens near to the posterior end, and extending straight and parallel 

 backward, ending in the elevation between the eyes; antenna? 12-joiuted, iu- 

 .serted on the anterior margin of the frontal carinse at the edge of the clypens, 

 the scape tolerably long, extending lieyond the posterior margin of the head, 

 flagellum nearly setaceous, only feebly thicker at a])ex than at base, the first 

 joint longest, the next following until the penultimate gradually longer, the 

 spindle-shaped apical joint also longer; frontal area triangular, somewiiat longer 

 than broad and very indistinct; frontal groove always indistinct; ocelli absent; 

 eyes tolerably small, oval, placed almost in the middle of the ujjjier side of the 

 head, between the cheeks and the hind angles ; occiput emarginate posteriorly : 

 prothorax above hemispherically convex, sloping gradually to the mesothorax at 

 the end of which it is most deeply imi)ressed ; metathorax abruptly elevated, 

 strongly gibbous, ^slightly longer than broad ; abdouuii moderately small, the 

 petiole with an erect, tolerably short and thick scale ; posterior femora somewiiat 

 longer than their tibiie, spurs pectinate, claws simide. 



This genus .seems closely tillieil to the next, diilefiug chiefly in the 

 form of the aiitennse and in the absence of the ocelli. 



