64 THE CANADIAN ENTOMOLOGIST 



of the cell and of cell 1st M2; cross-vein m connects Afi+2 with 

 Ms, weak and tending to atrophy; Cui. leaves Ah before mid- 

 length of the long cell 1st Mi. 



Abdomen elongated, tergites dark brown, the caudal margins 

 of the segments narrowly paler; basal sternites more yellowish 

 than the terminal segments; hypopygium brown. 



Habitat. — Alaska. 



Holotype, d^, Sitka, Alaska; June 16, 1899 (Kincaid). 



Allotype, 9 , Saldovia, Alaska; July 21, 1899 (Kincaid). 



Paratypes, o^ 9 , Yakutat, Alaska; June 21. 1899 (Kincaid): 

 cf, Virgin's Bay, Alaska, June 26, 1899 (Kincaid); cf, Saldovia, 

 Alaska, July 21, 1899 (Kincaid). 



The type is in the collection of the United States National 

 Museum; the species is based on material taken on the Harriman 

 Expedition, and was determined by Coquillett as being T. debilis 

 Will. 



The species agrees with debilis in many respects, but the general 

 coloration is dark brown, not yellow; the basal segments of the 

 antennae are not reddish and the venation is different, the cells 

 1st Ml and Mi being greatly elongated. The abdomen and 

 halteres are longer than is usual in this group of the genus. 



GEOMETRID NOTES. 



The Genus Dysstroma Hubner. 



by l. w. swett, west somerville, mass. 



The genus Dysstroma Hiib. (Verz. p. 333, 1825) with its 

 type truncata Hufn. seems to be a natural group by itself. Hulst 

 (Trans. Am. Ent. Soc, vol. XXIII, p. 283, 1896) under Hydriomena, 

 cites truncata Hufn. as the type of Dysstroma. Warren and 

 Hampson both refer the truncata group to Polyphasia Stephens, but 

 treat it as a separate genus (Proc. Zool. Soc, p. 373, 1893, and 

 Ind. Moths, III, p. 378). Mr. L. B. Prout points out in Trans. 

 London Ent. Soc, part XVIII, p. 33, 1908, that Po/j^/m^m cannot 

 hold, as Hiibner's name Dysstroma has priority. According to 

 Mr. Prout's and my own views, what we have been calling truncata 

 in North America is really citrata Linne ("Fauna Suecica," ed. II, 

 p. 332, 1761). 



February, 1917 



