582 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



along sides of head dorsal to eyes and covered by ex- 

 tended lateral margins of head; antennae 11-jointed 



Cryptocerus 

 Antennal fossae of a different conformation or antennae of a 

 different number of joints 4 



4. Postpetiole articulated to dorsal surface of gaster, which 



is flattened dorsally, more convex ventrally, and pointed 



at tip Crematogaster p. 585 



Postpetiole inserted at anterior end of gaster, which is of 

 the usual shape 5 



5. Antennae 6-jointed; head cordiform, antennal fossae as long 



as scapes Strumigenys 



Antennae with more than six joints 6 



6. Antennae 11-jointed; without a distinct club or with a club 



consisting of only a single joint 7 



Antennal club consisting of several joints, or antennae not 

 11-jointed 10 



7. Integument rough, bearing stiff or hooked hairs 8 



Integument smoother; hairs scale-like and appressed 



Cyphomyrmex 



8. Large species; workers highly polymorphic; head with a 



pair of occipital spines only; thorax with three pairs of 



dorsal spines or tubercles Atta (s. str.) 



Small species; workers monomorphic or feebly polymorphic; 

 thoracic dorsum with four pairs of spines or tubercles 9 



9. Head broad with rounded occipital lobes, without supraocu- 



lar spines or tubercles Atta (Moellerius) 



Head narrow, with angular occipital lobes; body rough, cov- 

 ered with small tubercles Atta (Trachymyrmex) 



10. Antennae with a 2-jointed club n 



Antennal club, when developed, with more than two joints 12 



11. Antennae 10-jointed, epinotum unarmed Solenopsis p. 584 



Antennae 11-jointed, epinotum dentate Erebomyrma 



12. Posterior margin of clypeus elevated in the form of a welt 



or ridge bordering antennal fossa in front 13 



Posterior border of clypeus not thus elevated 15 



13. Portion of clypeus in front of antennal insertion narrow but 



not reduced to a mere ridge; antennae of male 10-jointed. . 14 

 Portion of clypeus in front of antennal insertion reduced to 

 a mere ridge; antennae of male 13-jointed ..Myrmecina p. 584 



14. Antennae 12-jointed Tetramorium (s. str.) 



Antennae 11-jointed Tetramorium (Xiphomyrmex) 



15. Antennae 1 i-jointed 16 



Antennae 12-jointed 19 



