ZETHUS. 33 



% . Clypeus transverse quadrate, either wholly pale-yellow, or 

 only its lower part; inferior margin entire and arcuate ; the last 

 two articles of the antennae tawny beneath. 



Var. a. Two yellow spots on the scutellura. 



b. The yellow mark of the frontal ridge and that on the post- 

 scutel, interrupted; the face presenting but two yellow points. 

 The border of the prothorax is sometimes sprinkled wiih black 

 dots. 



c. The yellow markings hardly visible. Prothorax black. 

 Legs black; wings a little smoky,, with some ferruginous tints and 

 the nervures brown. 



d. The spine of post scutel yellow or black. 



e. In small specimens, principally % , the spine is obliterated, 

 or replaced by a little longitudinal carina. 



/. The peduncle of the 2d segment rather longer; the spine 

 of post-scutel obliterate. 



g. The extreme edge of the clypeus % black, or partly black, 

 which causes very fallacious appearances. 



Ress. a. cliff. — This species is very distinct, by its ridges, 

 prominences, and rugosities, by the very large punctures of its 

 petiole, and especially by the long spine of its post-scutel. 



Hab. The gulf side of Mexico, in the warm parts. Tarn auli pas, 

 Huasteca, etc. Very common in Tampieo. I have taken a score 

 of specimens in view of the town of Pueblo-Yiejo, against posts 

 exposed to the sun. Various specimens also from Orizaba. 



Fig. 2. The insect seen in profile, enlarged. 2, 6. Its natural size. Fig. 

 2, a. The abdomen more enlarged. 



20. Z. imitator n. pp. — Niger, crasse, dense punctatus: metanoto 

 minus crasse pnnctato ; petiolo ovato-cylindrico, crassissime cribrato ; 

 punctis 2 clypei ; 2 frontis, pronoti margine, macula subalari, tegularum 

 limbo, scutelli fascia interrupta, post-scutelli fascia, maculis 2 metanoti, 

 abdominis segmentorum l°-3° limbo anguste, tibiinque iutermediis basi 

 extus, flavis. J • 



Total length, 12^ mm. ; wing, 9 mm. 



9. Form and sculpture about the same as in spinosus. Head 

 small. Clypeus much rougher, very coarsely and confluently 

 punctured, not broad, but rounded, more prolonged and truncate. 

 A carina between the antennas, prolonged on the clypeus. The 

 rest of the punctuations about the same, very rough. Prothorax 

 3 



