LARVAL TAXONOMY OF THE TROGINAE IN NORTH AMERICA 13 



not recently moulted. The epipharynx and hypopharynx of many 

 Trox and Omorgus evidenced areas which had been so damaged. 

 Often many dissections were necessary to find an undamaged epi- 

 pharynx or hypopharynx. 



Terminology 



The terminology used in this report is essentially that employed by 

 Boving (1936 and 1942) and Ritcher (1966). Where necessary a few 

 additional terms have been used to facilitate the description of certain 

 structures and areas. 



The term "fused phobal mass" is used to denote the large, coalesced 

 group of phobae located on each side of the pedium slightly anterior 

 to the tormae (fig. 2). 



The terms "subtorma" and "subapotorma" have been used to aid 

 in the description of the hypopharynx. In each case the prefix "sub" 

 has been affixed to the term used for a similar structure occurring on 

 the epipharynx. The prefix "sub" is used as these structures occur on 

 the dorsal surface of the submentum and ventral to similar structures 

 of the epipharynx. 



The term "subtorma" refers to the heavily sclerotized, transverse, 

 curved process located near the proximal border of the hypopharynx. 

 The subtormae of Trox and Omorgus are nearly symmetrical and have 

 strongly produced anterior and posterior projections at their outer 

 margins. The subtormae are usually joined medially (figs. 10, 12, 

 and 19). 



The term "subapotorma" refers to the heavily sclerotized process 

 extending forward from the subtorma on each side mediad of the 

 longitudinal row of inwardly directed, closely set phobae of the hypo- 

 pharynx (figs. 10, 12, and 19). 



The various lobes of the thorax and abdomen of the larvae have been 

 assigned names in this dissertation which differ from those generally 

 employed in the past. Most workers have adapted the terminology 

 normally used for the sclerites of the adult insect thorax for use on the 

 larvae. Terms such as "prcscutum," "scutum," "scutellum," et cetera, 

 have been used to refer to the diff"erent lobes of the segments of the 

 thorax and abdomen of soft bodied larvae. This writer concurs with 

 Butt, however, in the usage of a simplified terminology for the larvae 

 distinct from that employed for the well-defined sclerites of the adults.® 

 Butt in his work on the larval musculature of the Scarabaeoidea has 

 restricted his approach to a recognition of lobes and of the folds which 

 set off these lobes. He has recognized the following for the abdominal 

 segments of the larvae: dorsal lobe one (DLl), dorsal lobe two (DL2), 



8 Personal communication with Dr. F. H. Butt. 



