SMULYAN: NEW ENGLAND TENTHREDELLA. 385 
The more notable past and present workers in this genus are 
Norton, the elder Cresson, MacGillivray and Rohwer in this 
country; Provancher, Harrington and W. F. Kirby in Canada; 
Konow and Enslin in Germany; and Cameron and W. F. Kirby 
again, in Great Britain. 
History of Tenthredella. 
Up to 1910 this genus bore the name Tenthredo, a genus 
established by Linnaeus in the 4th edition of the Systema Na- 
turae (1744), being the first of the four genera which composed 
his new order Hymenoptera, and included by him in the 10th 
edition of the same in 1758. The new name Tenthredella was 
applied by S. A. Rohwer in 1910 (Proc. U. S. Nat. Mus., vol. 39, 
p. 117, 1910), who found that Tenthredo Linn, was not a valid 
name for this genus, that is, the Tenthredo of authors. 
According to Rohwer, Latreille fixed Tenthredo scrophulariae 
L. as the type of Tenthredo in 1810. Tenthredo scrophulariae 
L., however, belongs to the genus Allantus Jurine and was named 
as the type of that genus by Curtis in 1839. Allantus Jur. and 
Tenthredo L. are therefore isogenotypic. Tenthredo L. equalling 
Allantus Jur., Tenthredo of authors had no name (Rethra Cameron 
not being a synonym of Tenthredo of authors according to Rohwer) 
and he therefore gave it the name Tenthredella. 
Tenthredella Rohwer. 
Type: Tenthredo atra Linnaeus. 
Owing to the diversity of opinion which exists as regards the 
definition of Tenthredella in relation to Tenthredo L. (formerly 
Allantus Jur.) the writer has deemed it advisable not to adopt a 
definition of the genus as a whole in the present paper, and his 
distinction between the two genera is based merely on the species 
of the two as they are found in the geographical area to which he 
has limited himself. For this reason no synonymy of Tenthre- 
della is given. 
Ch.\racters of Tenthredella. 
Body usually elongate and rather slender; eyes reach close to 
clypeus, their inner margins strongly convergent vontrallj'; 
clypeus emarginate; inner and upper margins of the antennal 
