ODYNERUS. 155 



c. Segments 1, 2 only, of the abdomen bordered with yellow. 



4. S. detoilis n. sp. — Niger, punctatus, maxime elongatu.s, gracillimus; 

 postscutello et metanoto rugosis; hoc maxime pone post-scntellnm 

 producto ; abdominis primo segmento elongato, grosse punctato, sulco 

 valde diviso; puncto frontali et post-oculari, punctis 2 scutelli, macula 

 subalari sulfareis ; abdominis segmentorum l' 1 , 2' fascia marginali sul- 

 furea, secunda interrupta ; tibiis basi sulfareis ; alis hyalinis, tegulis 

 fusco-nigiis. J . 



Total length, 8.5 mm. ; wing, 7 mm. 



9. Small and extremely slender. Form much lengthened. 

 Head large, higher than wide; antennas inserted notably below 

 the middle of its height. Clypeus widely and not deeply hol- 

 lowed, subbidentate, a little rugose toward the bottom. Head 

 finely punctured. Thorax very long; prothorax punctured, 

 finely rimmed, forming on each side a very small tooth. Meso- 

 thorax and clypeus little punctured; this last divided by a very 

 large groove. Post-scutel and metathorax very rugose; the first 

 flattened obliquely, bordered before; the second strongly pro- 

 longed behind; its concavity oblique, strongly hemmed, especially 

 toward the top a little striate. 



Abdomen very long and slender. The first segment of a 

 lengthened funnel-shape, longer than wide, its suture very strong, 

 a little angulate in the middle ; its surface very coarsely punctured 

 and divided by a wide and strong groove. The remainder 

 smooth. Insect of a shining black; a spot between the antennae, 

 a dot behind each eye, two spots on the prothorax, one beneath 

 the wing, two dots on the scutellum and the marginal belt of the 

 first segment of the abdomen, sulphur-yellow; the 2d segment 

 ornamented with a yellow border (sometimes interrupted), which 

 is almost wanting beneath. Legs black. Tibiae and anterior 

 tarsi and the superior moiety of the tibiae of the other pairs, yel- 

 low; tarsi ferruginous. Wings transparent, a little brown on 

 the side about the stigma. Wing scales brown or black. 



Var. On the 4th segment a trace of a border and at times a 

 dot at the summit of the clypeus, yellow. 



%. Unknown. 



//ess. a. diff. — This little species differs essentially from the 0. 

 Philadelphia in its more slender form, in the head being higher 

 than wide, in its much prolonged metathorax. in its more rugose 

 first segment, its very much more decided suture, and in the yd- 



