AMERICAN HYMENOPTERA. 385 



deep; the following 3 furrows being also smooth and deep, but narrower. Cal- 

 caria fuscous. Legs densely covered with white hair, much more densely than 

 in I. Mathewi. The apical abscissa of .the radius is shorter compared with the 

 basal, than it is in Mathewi. Length 7 mm. % . 



Rah— West Coast of Mexico. (G. F. Mathew, R. N.) 



Rliogas aztecus sp. no v. 



Ferruginous, the flagellum of the antennae and the tips of the mandibles black; 

 the wings hyaline, the stigma dark, the uervures light fuscous. Palpi dark 

 testaceous, covered with white pubescence. %, . Length 7 mm. 



Head alutaeeous, almost punctured. Eyes coarsely facetted. Thorax finely, 

 closely, distinctly punctured. Scutellar depression deep, the base and apex with 

 oblique straight slopes, meeting in the centre below. Median segment more 

 rugosely punctured than the rest; there is a distinct keel extending from the 

 base to the top of the apical slope ; in the centre of the latter, at the apex, are 2 

 short, fine keels ; on the apex of the sides is a short, stouter keel. The 1st, 2nd 

 and 3rd abdominal segments to shortly beyond the middle are closely, longitudi- 

 nally striated, and all are keeled down the centre; the apex of the 3rd and the 

 following segments are smooth and shining. The second cubital cellule is nar- 

 rowed towards the apex ; the 3rd abscissa of the radius is twice the length of the 

 2nd ; the transverse median nervure is received shortly behind the middle of the 

 cellule. 



The propleurse are more or less striated ; the centre of the mesopleurse shin- 

 ing. First abdominal segment slightly longer than the second, which is longer 

 than wide, and is distinctly margined, almost keeled, along the sides. Legs 

 densely covered with white pubescence. Malar space nearly as long as the an- 

 tennal scape. Eyes clearly converging above. Temples as long as the top of the 

 eyes. 



Hab. — Mexico. 



This species cannot well be mistaken for any of the few recorded 

 species of Rhogas from Central America. 



Agathis ? tricarinata sp. nov. 



Black ; the basal segment of the abdomen entirely, the 2nd above to shortly 

 beyond the middle, entirely below, as is also the base of the 3rd ventral segment 

 of the metauotum, bright red ; wings dark fuscous, a hyaline cloud, broadest be- 

 hind, on the fore wings, commencing near the apex of the stigma; the hind 

 wings entirely fuscous. 9- Length 7 ; terebra 4 mm. 



Smooth, impuuctate, the mesonotum with 3 distinct keels in the centre, placed 

 nearer the base than the apex. From the sides of the anterior ocelli (but not 

 touching them) two stout keels run to the antennas where they unite; opposite 

 their base a similar keel runs to the eyes. The 5-jointed maxillary palpi are pale 

 testaceous, except at the base. Mandibles pale testaceous at the base. Malar 

 space not quite half the length of the eyes. Scutellum keeled above on the sides 

 and apex. Sides of metanotum keeled ; in the centre are 2 not very distinct 

 keels close together, which unite with a stouter keel bordering the top of the 

 apical slope. Apex of mesopleune dilated on the upper half; the depression 

 widened below and with 3 stout teeth. Base of first abdominal segment dilated 



TEANS. AM. ENT. SOC. XXXI. (49) OCTOBER, 1905. 



