278 IIYMENOPTERA OP AMERICA. [PART I. 



9T. O. forniOSJJS Sauss. — 0. Cordovce conformis, at metathorace dis- 

 tincte bidentato; abdomine magis conico ; niger, inandibulis, clypeo, 

 scapo, capitis maculis, fulvi.s ; pronoto, tegulis, macula subalari, maculis 

 2 scutelli, post-scutello, metanoti angulis, -abdominis segmentoruua 

 marginibus (priini limbo utrinque cum fascia obliqua conjuncta), pedi- 

 busque, flavis vel aurantio-vaiiis ; alis subferrugineis, apice griseis. 



Odyn. formosus Sauss. Rev. de Zool. XXII, 1870, 59, 15, £. 



Total length, 10 mm. ; wing, 8 mm. 



£. Size and form nearly as in 0. Curdovse, but the metathorax 

 has its angles on each side produced into a distinct tooth ; the 

 cavity not at all limited, not margined superiorly on each side 

 by a little oblique ridge; the abdomen quite conical, the first 

 segment as broad as the second, and more sharply truncate at 

 base ; the punctured marginal band of the 2d segment decidedly 

 impressed, a little widened in the middle. 



Black ; mandibles and feet rufous or orange. Clypeus, frontal, 

 ocular and post-ocular maculae, yellow or rufous. Antennas 

 black; scape yellow, a little obscure above. Prothorax, a spot 

 under the wing, tegula;, two spots on the scutel, post-scutel, 

 angles of metathorax, and margin of all the abdominal segments, 

 yellow or rather orange ; the fascia' wide ; that of the first seg- 

 ment fusing' into two oblique lateral bands, which make nearly 

 an anterior interrupted fascia, sometimes rufous. Anus rufous 

 or yellow. Wings rather ferruginous; the apex clouded. 



Var. A. black spot on the posterior angles of prothorax. — A 

 yellow fascia on scutel. 



Bess. a. diff. — This docs not seem to be a variety of 0. Cor- 

 dovse. It has the same livery as O. Boscii, turpi*, molestus, 

 but a quite differently shaped metathorax; it is also smaller and 

 more slender, nearly one-half smaller than the first. It resembles 

 ( ). sulfureus, but its livery is not so rich nor so pale ; the clypeus 

 is not so much produced, the size smaller. It is allied closely 

 also to 0. annulaius, although smaller and with a metathorax 

 not so much flattened behind. Comp. also 0. annulatus (Mexi- 

 can variety). 



Hab. The temperate parts of Mexico. Oriental Cordillera 4 

 9 (Sumichrast). 



98. O. spectaliilis Sauss. — Niger, gracilis ; capite, thorace abdomi- 

 nisque Begmentorum 2 1 — 5 1 margine dense punctatis ; metanoto rotun- 

 dato, utrinque valde augulato ; abdomine subconico ; clypeo, antennis 



