78 HYMENOPTERA OF AMERICA. [PART I. 



inflated petiole, shorter 2d segment, with rather sinuated margin, 

 etc. See also the E. Nortoniana and Cressoniana. 



Hab. The Gulf side of Mexico. ([ have taken some specimens 

 of it at Tampico.) The Oriental Cordillera, Banio (Mr. Sumi- 

 chrast). 9 9,5 %. 



Nota. — Mr. Sumichrast attributes to this insect a most interest- 

 ing nest. It is formed of a mass of cellules or habitations com- 

 posed of a black bark which seems to be agglutinated by some 

 gummy material. These habitations are more or less cylindrical 

 and gummed one against another. But although they form a 

 double row, they are not always parallel like the cells of social 

 wasps, but a little oblique the one upon the other, which renders 

 their arrangement quite irregular. This nest is fixed upon a 

 little branch of the oak. It greatly resembles in its system that 

 of Zethus Bomajidinus, which I have cited as apropos of this 

 species. But its surface, instead of being fibrous, is here cellulous- 

 rugose; one remarks here some little rounded or polygonal cells, 

 the borders of which form a sort of reticulation, which is, how- 

 ever, but a simple sculpture ; the fosscttes are too small to be 

 compared to basal sockets, and have absolutely nothing in common 

 with the outlines of cells which one often finds on the borders of 

 wasps' nests. I should not be surprised if this nest should be 

 rather that of a Zethus than of the E. mejricanus, and that it 

 should prove to be an error in the " etiquette" mark. 



16. E. Simiiclirasti n. sp. — Cr.-issiuscnlns, nig^r; clypeo bidentato ; 



thorace quadrato, tenuissime ruguloso; abilomine nitido, petiolo sparse 

 punctato, camparmlato, incrassato-marginato ; apice sulco diviso ; frontis 

 macula, raargine postico pronoti, abdominis segmentorum l 1 , 2'' limbo, 

 post-scutelloque. flavis. $ • 



Total length, 11 mill. ; wing. 8.3 mill. 



?. Quite closely related to E. Mexicanus. A little larger. 

 Clypeus bidentate, not so much flattened. Thorax a little longer, 

 not so distinctly punctured but quite delicately sh a greened all 

 over. The petiole more carnpanulate, wider, truncate; much 

 swelled, also bordered by a salient cordon, but parted by a groove 

 with a shallow impression before the border; 2d segment rather 

 elongate, the lamellar e(\ge very narrow, hardly distinct, although 

 the first edge is not thick. 



Black, with grayish-silky reflect ion ; abdomen silky-shining, 





