THE CANADIAN ENTOMOLOGIST, 239 



frequently semicircular, always wider than long, while the middle tibise 

 have two distinct apical spurs, characters of great taxonomic value, 

 readily recognizable, and which at once separate them from the 

 Bembicidie. 



The genera are not numerous, and may be separated as follows : 



Table of Genera. 



Anterior ocellar cicatrice elliptic, round or reniform 2. 



Anterior ocellar cicatrice linear, transversely arcuate. 



Metathorax excavated posteriorly, compressed laterally ; last ventral 

 segment in ^ endings in 3 spines ; mandibles dentate ; maxillary 



palpi 6-, labial palpi 4-jointed Bembidula, Burm. 



Metathorax flat or convex posteriorly, not compressed laterally ; last 

 ventral segment in ^ ending in a single spine. 



Mandibles dentate ; maxillary palpi 4-, labial palpi 2- 



jointed Bembex, Fabr. 



Mandibles edentate ) maxillary palpi 3-, labial palpi x- 



jointed Microbembex, Patton. 



2. Front ocellar cicatrice round or reniform ; maxilla short ; maxillary 



palpi 6-, labial palpi 4-jointed Monedula, Latr. 



Front ocellar cicatrice elliptic ; maxilla long, attaining the hind coxae ; 



maxillary palpi 3-, labial palpi i-jointed Steniola, Say. 



North American Species. 



(i) Bembidula, Burmeister. (3) B. insignis, Hdl. 



(i) B. variegata, Olis. =Belfragei, Cr., pars. 



(2) B. quadrifasciata, Say. (4) B. spino]£e,Lepel. 



(3) B. insidiatrix, Hdl. (=fasciatus, Auct.) 



(4) B. parata, Prov. (5) B. similans. Fox. 



(5) B. capnoptera, Hdl. (6) B. Sayi, Cr. 



var. mesillensis, Ckll. (7) B. texana, Cr. 



(6) B. fodiens, Hdl. (8) B. troglodytes, Hdl. 



(7) B. diodenta, Handl. (9) B. convexus, Fox. 



(8) B. decisa, Taschaub. (10) B. cinerea, Hdl. 



(9) B. viduata, Handl. (11) B. nubilipennis, Cr. 

 (10) B. Burmeisteri, Handl. (12) B. pruinosa. Fox. 



(2) Bembex, Fabricins. (13) B. occidentalis. Fox. 



(i) B. amoena, Hdl. (14) B. uscripta,Fox. 



(2) B. Belfragei, Cr. (15) B. multipicta, Smith. 



=i(Cressoni, Hdl.) (16) B. pallidipicta, Smith. 



