1902.] XATURAL SCIENCES OF PHILADELPHIA. 65 



striate than iu eorumbce, bordered above by a ridge terminating at 

 the postero-lateral angles which are obtuse; abdomen rather dis- 

 tinctly iHinctuved throughout, especially beneath, except the last 

 doi-sal which has microscopic punctures ; wings yellowish-ferruginous 

 basally as far as stigma, the veins of the same area similarly col- 

 ored, those beyond including stigma brownish, marginal cell more 

 or less fuscous. Length 13 mm. 



Chapada (February, October). Two specimens. 



Odynerus (Odynerus) sericeus n. sp. 



$. — Black; with dense sericeous pile, especially on abdomen; 

 apex of clypeus, spot on inner 'orbits near clvpeus, on mandibles 

 basally, fore and hind margin 'of prouotum, line on postscutellum, 

 irregular lines on middle segment bordering the concavity above 

 at either side, tips of femora obscurely, line on fore tibiae inter- 

 nally, and spot on tegulse at base, yellow ; abdomen entirely black ; 

 tarsi testaceous. Head strongly punctured, but less so than in 

 chapadce, the punctures of front rather close ; clypeus about as 

 broad as long, closely punctured, with two elongate, polished tuber- 

 cles medially, strongly bidentate apically, roundly emarginate 

 between teeth ; the thorax is quite similar to chapadce, but on the 

 whole the punctuation is not so coarse, and the postsculellar crista 

 is feebler; strise of concavity of middle segment stronger; abdo- 

 men distinctly punctured throughout; wings subhyaline stained with 

 fuscous along costa, nervures black. Length 12 mm. 

 Chapada (March). One specimen. 



Odynerus (Stenodynerus) serratus n. sp. 



cJ'. — Black; with sericeous yellow-brown pile; triangular spot on 

 mandibles basally, two dots at base of antennae, scape beneath, line 

 on medial tibiaj, and a broad fascia at apex of segments 2—6, tlie 

 seventh entirely, yellow; tegulae with a testaceous spot. Form 

 elongate; head strongly punctured, the punctures smaller and 

 fewer on occiput; clj'jDeus a little longer than broad, with large, 

 shallow punctures, broadly emarginate, or, in other words, with two 

 large widely separated teeth; thoi*ax coarsely punctured; scutellum 

 slightly impressed down middle; dorsal surface of middle segment 

 longer than postscutellum, rugoso-jjunctate, armetl posteriorly with 

 a large, serrated crest, which is broken medially; posterior surface 

 of middle segment smooth, polished, strongly concave; sides with 

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