THE CANADIAN ENTOMOLOGIST. 



the appendage is less arched and the apices not so strongly recurved. 

 Tlie hairs on the upper surface are shorter and not so dense. The inferior 

 appendage is a little more than half as long as the superiors. Elongata 

 also differs in the much brighter and better defined yellow markings on 

 the sides of the thorax and second abdominal segment, which, however, 

 have mucli the same form and distribution. The brown of the legs is 

 reduced to the coxae and a streak along the proximal half or more of the 

 upper surface of the first femora. 



The dorsal view of the ^ appendages is in some respects more like 

 that of S. minor. Calv., but the superiors in the latter are relatively shorter, 

 more slender, and are more widely separated at base, the apices are not 

 so much upcurved and the hairs are much shorter and more thinly and 

 evenly distributed. The basal tooth is smaller and the inferior carina 

 bears a prominent tooth as in elongata. 



Of European species Williamsoni comes nearest to S. flavomaculata 

 (Lind.), but differs from it quite obviously in both appendages and colour- 

 pattern. 



Described from lo $ $, 3 % 'i  Toronto, June, 1901, i ^ in 



house ; De Grassi Point, Lake Simcoe, Ont., June 29-Aug. i, 5 c? J , 3 



$ $ ; Temagarai, Ont, Aug. 15, 1906, \$ (P. Hahn.) ; Oden, Mich., 



Aug. II, igo6, 2 $ $ (E. B. Williamson) ; Bone Pond, Saranac Inn, N. 



Y., July 26, 1900, I ^ (J. G. Needham). 



The known range of this species, including the Sherbrooke record, is 

 thus from Quebec and north-eastern New York to northern Ontario and 

 Michigan. It belongs, apparently, to the Canadian and Transition Zones, 

 being evidently rare at Toronto, which lies towards the southern boundary 

 of the Transition Zone, but much more numerous northward. 



I take pleasure in naming this insect after Mr. E. B. Williamson, who 

 has shown me many favours of late and given me a great deal of valuable 

 advice and assistance in my studies of dragon-fly life. 



He writes me that his specimens were taken about 4 p. m. on Aug. 

 II, 1906, " at the mouth of the Minnehaha, a small stream flowing into 

 Crooked Lake, Oden, Michigan. The Minnehaha, as it approaches 

 Crooked Lake, pursues a circuitous course through a large prairie-like and 

 marshy tract. The Somatochloras were observed feeding along the shore 

 line among the rank cattail or Sparganium growth just at the water's edge. 

 They were leisurely in their movements, spending much time at a place, 



