NORTH AMERICAN HYiMKXOPTEKA. 235 



urea large, broad, always more or less pubescent. ^laiidibles notched 

 outwardly, the notch generally broad (in T. obscurus and in the West 

 Indian T. insukiris) it is very narrow and situated about the middle, 

 their inner margin generally bidentate* Anterior ocelli round and 

 distinct, the jjosterior pair flat, narrow and elongate, placed oblifjuely. 

 Marginal cell elongate, generally lanceolate or rounded at tip, the 

 appendiculation small and sometimes indistinct. Size variable. 

 The genus may be divided into two sections as follows: 



Fore coxfp of male simple: fore femora of male beneath, near the base, entire 

 females with the thorax generally densely pubescent SECTION I 



Fore coxtB of males with an elongated process ; fore femora of male lieneath, 

 near the base, emarginate ; thorax of females not densely pubescent. 



SECTION II. 



The females of the tirst section are generally short, robust insects, 

 while those of the other section are rather long and narrow, and 

 never have the clypeus produced medially as the majority of those 

 of the first section do. In some respects the Section II agrees with 

 Tachysphex, but the spines on fore tarsi of female are not long and 

 flexible, and the pygidium is hairy. 



SECTION I. 



FEMALES. 



1. — Clypeus with the anterior margin, in the middle, produced into a large 



quadrate tooth or lobe, and with several smaller teeth laterally 2. 



Clypeus with the anterior margin not or scarcely i)r()dnced into a lobe, at 



the most thickened in the middle 7. 



2. — Metanotum strongly sulcate medially 6. 



Metanotum not strongly sulcate medially 3. 



3. — Third joint of antennse about one-quarter longer than the fourth 4. 



Third joint of antenn?e equal to, or but little longer than the fourth 5. 



4. — Thorax densely clothed with golden-yellow pubescence, so that the sculp- 

 ture of the metanotum is hidden. Length 18—22 ram validiiiK. 



Thorax sparsely clothed with grayish pubescence: metanotum finely granu- 

 lated (four hind tibise within with a dark stripe). Length 12 — 14 mm. 



liai'pa.v. 



5. — Median ])rocess of clypeus divided into two distinct lobes; space between 



the eyes at top equal to the length of joints two and three of antennae, 



the latter joint, in length, about equal to the fourth; front and thorax 



with golden pubescence praMlafor. 



Median process of clypeus not bilobed. its apex simply incurved ; third an- 

 tenual joint slightly longer than the fourth; front and thorax clothed 

 with silvery -gray pubescence ealcaratiis. 



* In some species of Section II the mandibles have but one tooth within. 



TRANS. AM. ENT. .SOC. XIX. AUGUST, 1892. 



