46 PROCEEDINGS OF THE NATIONAL MUSEUM voi^no 



hruneri. Pettit and McDaniel (1918) treated the Michigan population 

 as alaskanus. Essig (1926, p, 81) listed alaskanus as a synonym of 

 hruneri. Hebard (1925a, p. 114) questioned the synonymy indicated 

 by Walker, and later said (1928, pp. 281-282) he believed alaskanus 

 to be a geographic race of mexicanus if nominal rcognition is war- 

 ranted. Rehn (1952) agreed with Hebard's opinion. 



Because of the difference of opinion concerning alaskanus, it may be 

 helpful to discuss the type in more detail. It is the specimen selected 

 by Rehn and Hebard, and was received at the U. S. National Museum 

 on Feb. 29, 1892, from T. C. Mendenhall of the U. S. Coast and Geo- 

 detic Survey. Accession records show that the material was collected 

 by J. E. McGrath during an expedition which was active along the 

 Alaskan Boundary during September 1890-May 1891. McGrath 

 (1893) has described the general experiences of the party which he 

 led up the Yukon River, and (p. 185) has commented about the plenti- 

 ful insects found near the river in summer. It appears that the type 

 specimen was collected along the Yukon River somewhere between 

 Ft. Yukon and the 141st Meridian. 



A male of hruneri, collected in 1948 near Fairbanks, Alaska, a 

 locality at about the same latitude as the intersection of the Yukon 

 River and 141st Meridian, confirms the presence of this species in 

 Alaska, so there is no reason to doubt the source of the alaskanus 

 lectotype. Hebard did not examine the aedeagus of the lectotype and 

 so did not have this evidence which shows agreement with hruneri. 



Although hruneri, excelsus, and alaskanus were all described in the 

 same publication, the action of the first revisers (Hebard, 1928, for 

 excelsus; Walker, 1910, for alaskanus) establishes the precedent of 

 using hruneri as the valid name of this species. It is much the best 

 known of the three names, and has page priority in Scudder (1897b). 

 Though not required, page priority was recommended in the 1953 

 Copenhagen Decisions of Zoological Nomenclature when other con- 

 ditions are equal. 



Descriptive notes: A usually medium-sized, fully winged member of 

 the mexicanus group, most closely related to bilituratus, from which it 

 differs mainly in male genitalia. Mesosternal hump variable (fig. 

 l,g), averaging fully as prominent in male as in bilituratus, absent in 

 female; tegmina usually reaching slightly beyond tip of abdomen, 

 sometimes short of it. Females not always separable from bilituratus, 

 but in any given locality where both species occur hruneri females 

 usually more robust and often shorter-winged; males usually recog- 

 nizable by cercus and subgenital plate, but in doubtful cases the dorsal 

 valve of aedeagus of hruneri is highly distinctive in its much more 

 expansive and thin, striated, conformation. 



Male genitalia: Cercus (fig. 7,i) variable, usually about as in 



