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



D. plagiatus Mayr. 



The head and thorax of the worker are coarsely punctate or 

 foveolate and the gaster has large yellowish red spots. It nests 

 in the ground in small colonies. In other respects its habits re- 

 semble those of the preceding species. 



Rockville (H. L. V.) ; Colebrook (W. M. W.). 



Tapinoma Foerster. 



T. sessile Say. 



Evidently very common, especially in the southern portion of 

 the state. It nests under stones, dead leaves, logs, bark, etc., 

 usually in sunny places. The larvae and pupae are salmon-colored. 

 The workers emit a peculiar rancid-butter odor, the characteristic 

 " Tapinoma odor," which serves to distinguish them from all our 

 other eastern ants. 



Branford, New Haven, Stony Creek, Double Beach (H. L. 

 V.) ; Orange (W. E. B.) ; Colebrook ( W. M. W.). 



Camponotin^e. 

 Key to Genera. 



i. Antennae 9-jointed Brachymyrmex p. 591 



Antennae with more than nine joints 2 



2. Workers strongly polymorphic, i. e., with large-headed work- 



ers (majores) and small-headed workers (minores) and in- 

 termediate forms (mediae) Camponotus p. 600 



Workers not polymorphic though often of variable size .... 3 



3. Clypeal fossa distinctly separated from antennal fossa 4 



Clypeal fossa confluent with antennal fossa 5 



4. Antennal scapes and tibiae with erect hairs; mesonotum con- 



stricted but not subcylindrical .Prenolepis (Nylanderia) p. 591 

 Antennal scapes and tibiae without erect hairs; mesonotum 



strongly constricted and subcylindrical 



Prenolepis (s. str.) p. 591 



5. Second to fifth joints of funiculus shorter or not longer than 



succeeding joints; ocelli usually absent 6 



Second to fifth joints of funiculus longer than succeeding 



joints; ocelli distinct * 7 



6. Maxillary palpi 6-jointed Lasius (s. str.) p. 591 



Maxillary palpi 3-jointed Lasius (Acanthomyops) p. 594 



7. Fourth joint of maxillary palpi nearly as long as fifth 



Myrmecocystus 



Fourth joint of maxillary palpi a little longer than fifth 8 



8. Mandibles with broad dentate apical border Formica p. 594 



Mandibles narrow, falcate and pointed Polyergus p. 599 



