LARVAL FORMS OF COLEOPTERA 



Plate 21 



Histeridae, Helophoridae, SpercJieidae 



A. Helopliorns aquaticus L. (Denmark) : Head. Dorsal 



vieAv. 



B. Sperchens emarginatus Scliall (Denmark) : Maxilla. Ventral 



view. 

 C. 



D. Helophorus aquaticus 



E. 



F. Spereheus emarginatus 



G. 



H. 



I. Histeridae (British Guiana. Termitophil- 

 ous larva of unknown genus col- 

 lected by Dr. E. A. Emerson) 



Head. Y e n t r a 1 



view. 

 Larva. V e n t r a 1 



view. 

 Larva. V e n t r a 1 



view. 

 Leo". 



Ma'iidible. 

 Larva. Dorsal 



view. 



Larva. Lateral 

 view. 



128 



