268 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I4I 



Eciton burchelli (Westwood) 



Common name. — Army ant. 



Natural prey. — Cockroaches, Panama Canal Zone (Johnson, 1954; 

 Schneirla, 1956). 



Formica omnivora 



Synonymy. — The identity of this form is unknown. There are no 

 species of Formica on Ceylon. There was another Formica omnivora 

 described from tropical America, whose identity is also unknown (W. 

 L. Brown, personal communication, 1956). 



Natural prey. — Cockroaches, Ceylon (Kirby and Spence, 1822). 



Iridomynnex humilis Mayr 



Common name. — Argentine ant. 



Natural prey. — Cockroaches, injured individuals only (Ealand, 

 1915)- 



Lasius alienus (Forster) 



Natural prey. — Ectobius pallidus,\J.S.A., Massachusetts (Roth and 

 Willis, 1957). 



Pheidole megacephala (Fabricius) 



Common name. — Big-headed ant. 



Natural prey. — Holocompsa fulva, Hawaii (Illingworth, 1916). 



Nauphoeta cinerea and Pycnoscelus surinamensis, Hawaii (Illing- 

 worth, 1914, 1942) : The ants followed and killed A^. cinerea and P. 

 surinamensis as they burrowed in moist soil and attacked and de- 

 stroyed A'^. cinerea in breeding cages. 



XHI. VERTEBRATA 



Class PISCES 

 In British Guiana, Beebe (1925a) found undetermined cockroach 

 remains in the stomachs of four species of fish belonging to three 

 families, as follows : 



Family POTAMOTRYGONTIDAE 



Potamotrygon humboldti (Dumeril) 



(= Potamotrygon hystrix) 



Family PIMELODIDAE 

 Shamdia sebae Cuvier and Valenciennes 



