Robertson — North American Bees. 317 



Sphecodes confertus Say. 



Sphecodes confertxis Say, Bost. Jour. I, 392, 9, 1837, Lee. Edit. II, 771. 



Sphecodes falcifer Patton, Am. Ent. Ill, 230, tf 9, 1880. 



I have 48 5 specimens. In the female the fourth segment 

 of the abdomen is usually red, but sometimes partly or 

 wholly black. The fifth is usually black, but occasionally 

 almost entirely red. Patton says /S. falcifer may be distin- 

 guished from S. confertus by the fourth segment being red. 

 The specimens with only three red segments agree with Say's 

 description in the characters mentioned by him. This species 

 is smaller than S. dichrous. The most definite characters are 

 those mentioned by Patton : the unarmed mandibles and the 

 emarginate labrum. 



Sphecodes mandibulars Cress. 



Sphecodes mandibularis Cresson, Trans. Am. Ent. Soc. IV, 250, 9> 1872. 



Sphecodes mandibularis Provancher, Addit. Faun. Ent. Can. Hym., 335, 



C?9. 1889. 

 Twenty-two 5 and 13 $ specimens are referred to this 

 species. The female has the mandibles honey yellow, rufous 

 at tips, inner edge presenting a distinct tooth or dentiform 

 angle ; labrum short and rounded, testaceous or black ; vertex 

 and disc of mesothorax sparsely punctured, the latter shining 

 and with a greenish reflection ; semicircular iuclosure of 

 metathorax with a more or less salient rim, coarsely reticulated 

 or with irregular longitudinal rugae ; wings hyaline, nervures 

 testaceous or black; flagellum testaceous, especially beneath; 

 leo-s dull testaceous or black, tarsi paler; abdomen often 

 entirely red, or with the last three segments more or less 

 black. The male has rather conspicuous white pubescence on 

 the sides; flagellum testaceous, somewhat dusky above; 

 wings whitish, with pale nervures, and the tarsi pale; abdo- 

 men sometimes entirely black, or with the basal segments 

 more or less yellow. 



Sphecodes stygius Rob. 



Sphecodes stygius Robertson, Trans. Am. Ent. Soc. XX, 145, ^9» 1893 - 



I refer 12 § and 17 $ specimens to this species. This closely 



resembles S. mandibularis. The mandibles in the female are 



entire or toothed; vertex and mesonotum blacker and more 



closely punctured than in 8 . mandibularis ; antennae, tegulae, 



