310 



Mabgaeet Holliday, 



III. Other Ergatoid Forms. 



Erg'atoid forms of several otlier different species belonging to 

 Dr. Wheeler's collection were placed at mv disposal for study. 

 Unfortunatel}' tliese forms are too rare to be sacrificed for dissection, 

 and therefore a descriptioii of tlie exterual structure must suffice 

 uiitil sufficient fresli material is obtained to carry on a study of tlie 

 internal anatomy. It is assumed tliat tliese forms fuuctioned as 

 queens. 



Ponera opaciceps Mayr. 



Two ergatoid females of Ponera opaciceps were collected along 

 with many ordinary workers, by Dr. Wheeler in Mexico. The 

 ergatoid forms ditfer from the ordinary workers in the size of the 



Fig. G. 



Ponera opaciceps Mayr. 



a ergatoid female ; b worker. 



eyes and the structure of the thorax. The eyes of the ergatoid are 

 much larger than those of the ordinary workers, containing about 

 fifty-three faeets, closely and regularly arranged; the eyes of the 

 worker contained only about ten faeets, irregularly arranged and 

 not at all crowded. In the structure of the thorax very little 

 ditference is shown; in the region of the paraptera the segments 

 have not become fused to such an extent in the ergatoid form as in 

 the worker (Fig. G a and b). In coloriug, shape of head and ab- 

 domen tlie two forms are identical. Unfortunately no queen was 



