8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 94 



ventral. The bicondylar joints all have one condyle anterior and one 

 posterior with the exception of the trochantero-femoral joint which 

 has one dorsal and one ventral. The claws are thus placed one anterior 

 and one posterior. 



An isolated leg can usually be readily oriented. The shape of the 

 coxa will immediately determine the thoracic segment from which 

 it came. Whether the leg came from the right or left side of the 

 animal can frequently be told by the vestiture. On the coxae the vesti- 

 ture is generally lacking on the posterior aspect except as the tip. The 

 orientation of the posterior coxae can often be recognized at a glance 

 by the expansion over the base of the trochanter, which occurs only 

 on the anterior aspect. 



The wing venation has been interpreted according to the scheme 

 proposed by Forbes (1922). There was some hesitation, however, 

 in accepting this course, as it is believed by some writers that the 

 darker bands in the distal part of the wing do not represent veins 

 that are in any way homologous with any veins in other insect wings. 

 Certain parts can, however, be definitely correlated with other beetle 

 wings, so that the classification of the veins of this family is probably 

 as correct as that for the order as a whole. The spiracles of the 

 thorax are four in number. One pair is situated in the conjunctivum 

 between the prothorax and mesothorax on the ventral aspect, and 

 the other pair is in the membrane just anterior to the base of the hind 

 wing on the dorsal aspect. They are totally different in structure ex- 

 ternally, the former resembling the abdominal spiracles very closely 

 in appearance. They belong to the mesothorax and metathorax 

 respectively. 



The abdomen is lo-segmented in all staphylinids, and probably in 

 all beetles in a morphological sense. The last two or three segments 

 form the genitalia, whereas the first two are frequently much reduced 

 or united to the metathorax. In all staphylinids the first segment is 

 present only on the dorsum and is more closely united to the meta- 

 thorax than to the second abdominal segment. It is practically always 

 dissected ofif with the thorax. 



As far as the family Staphylinidae is concerned only the genitalia 

 have been treated in anything approaching a complete comparative 

 study, and even in that case there has been no comprehensive sum- 

 mary except that given for the males by Sharp and Muir (1912). 

 Their terminology has been followed chiefly, though it is rather arti- 

 ficial and obscures the true relationships. In the case of the genitalia 

 of the female, it has been found necessary to modify somewhat the 



