JOUENAL, OF ENTOMOLOGY AND ZOOLOGY 25 



ments together, the second segment not quite as long as the 

 two following united; claws with a tooth within. 



C'ornus rather long, but abnornially wide at base, barely con- 

 stricted in the middle, not altogether unlike the cornus of Sirex 

 areolatus; ovipositor extending a little more than twice the 

 length of the cornus beyond the tip of the latter. 



Length of the front wing 15 mm. ; of the cornus 2.7 mm. ; of 

 the ovipositor 15 mm. ; total length 20.5 mm. 



It gives me pleasure to dedicate this species to my friend and 

 former teacher. Dr. A. D. MacGillivray, in recognition of his 

 signal contributions to our knowledge of the Chalastogastra. 



Tremex Jurine 



Tremex, gen. treraicis, M. irr. <Tp^^<T£TpaiVa)=to bore through, derivatives: tremic + 



(Figs. 3, 9, 16, 36, and 38) 



<1761 Sirex Linnteus. Fauna sueicaj; ed. 2: p. 396. 

 <1762 Vrocerus Geoft'roy. Hist, ahreg. insec. d. Paris; v. 2: p. 264. 

 1807 Tremex Jurine. Nouv. meth. class. Hym. ; p. 80. 

 1837 Xylotrriis Ilartig. Faiii. d. Blatt. u. Holzwespen. ; p. 385. 

 1868 Xyloecematium Heyden. Ueber das seither unbek. < Manehen 

 von Xyloterus fuseicornis. <Berl. ent. Zeitselir. ; v. 12: p. 27. 



There is only one North American species. 

 Tremex columba (Linna?us) Lepeletier de Saint Pargeau 

 There are three fairly well marked races, of which heretofore 

 only two have been recognized. 



A Key to the Races of Tremex columba 



A. Entire Ijody fulvous; legs beyond femora yellow; wings dark red- 

 dish brown. Race sericeus Say. 



AA. Abdomen marked black and yellow. 



B. Ground color black ; second dor.sal segment, line at base of 

 third, broadened laterally, wedge-shaped spot on sides of 

 five following segments, the cornus at base, and .sometimes 

 spot on sides of nintli segment yellow ; head and thorax 

 varied with brown ; wings brown or yellowish. 



Race columha (Linna-us) Lepeletier de Saint Fargeau 



BB. Ground color yellow; apical line of second to seventh dorsal 

 segments; sometimes apex of eighth and more or less of 

 sides of ninth segments black: head, thorax and antennae 

 yellowish brown; wings yellow. Race aureus new race 



