ODYNERUS. 207 



abdominal segment cupuliform, notably less wide than the 2d, 

 coarsely punctured and rugose ; offering two irregular sutural 

 lines, between which is a fluting or transverse furrow, apparently 

 interrupted in the middle. Border of this segment thick. Second 

 segment ovoid, swelled, but longer than wide, strongly punctured 

 above, especially toward the border, which is a little retracted 

 and channelled. 



Insect black, clothed with a short grayish pile ; a spot on the 

 front, anterior border of the prothorax, post-scutel, a little dot 

 under the wing, and a regular border on the first two segments, 

 tawny-yellow. Tegulse ferruginous, bordered with yellow, or 

 yellow with a red dot. Legs black, tarsi and tibiae varied with 

 ferruginous or yellow. Wings sub-transparent, radius and radial 

 cellule brown. 



% . Clypeus yellow, punctured, terminated by a split beak (or 

 by two little separated teeth) ; bordered with black laterally. 

 Antennas black, with a yellow line on the scape. 



Bess. a. diff. — This little Odynerus is easily recognized by its 

 first abdominal segment fortified with two sutural lines. These 

 sutures are but little salient and the second above all (posterior) 

 can be known by the border of the fluting, rather than by a 

 suture. Nevertheless I think the insect well characterized by 

 the configuration of this segment. 



Hab. The temperate parts of Mexico. Mextitlan. 



I dedicate this pretty species to Don Jose Mariano Guzman, 

 the Mexican naturalist whose amiable hospitality permitted me 

 to explore the beautiful valley of Mextitlan. 



42. A. occidentalis Sauss. — Parvnlus, niger, punctatissimus, meta- 

 noti rugosi foveola rotundata, superne vix marginata ; abdominis valde 

 punctati secnndi segmenti margine paulura canaliculate) grosse punctate- ; 

 puncto frontali et post-oculari, pronoti margine interrupto, macula sub- 

 alari, tegulis, post-scutello. abdominisque limbo segmentorum supra 1, 

 2, 4, 5, 6 et subtus 2, 3, flavis.— £ . Clypeo bidentato, antennarum scapo 

 antice, litura oculorum et pedibus, flavis. 



Odynerus occidentalis Sauss. Rev. de Zool., IX, 1857, 274. 



Total length, 6.5 mm. ; wing, 5 mm. 



Size very small. Head circular. Ocelli large, arranged in a 

 regular triangle. Antennae inserted below the middle of the head. 

 Thorax wide before: its angles quite sharp, cut at a right angle. 

 Scutel parted by an indistinct longitudinal groove. Concavity 



