THE CANADIAN ENTOMOLOGIST. 49 



2. The flagellum is usually dark, but sometimes it is testaceous beneath. 

 I have 3 °. and 5 £ specimens. 

 Nomada denticulate, sp. nov. 



Nomada articulata, Rob., Tr. Am. Ent. Soc, xxii.: 124, £, 1895 

 (nee Sm.). 



Nomada articuiata, Rob., Tr. Acad. Sci., St. Louis, viii.: 51, $ , 1898. 



Synhalonia lllinomsis, sp., nov. — g . Differs from S. atriventris £ 

 in joint 3 of antenna? being one-half as long as 4. The form fuscipes 

 of S. atriventris, Tr. Acad. Sci., St. Louis, x.: 54, may be a distinct 

 species, and this may be the male of it. 



Agapostemon pulcher, Sm. — When writing the account of the local 

 species of Agapostemon, in Tr. Acad. Sci., St. L., vii.: 325-30, I found no 

 males of A. radiatus farther west than Nebraska, though I have since seen 

 them from Colorado. A form resembling A. radiatus ? was identified 

 as A. pulcher, Sm. A. femoratus, Crawford, Nebr. Acad. Sci., vii.: 162, was 

 identified as the male. 



Megachile petulans, Cresson (Trans. Am. Ent. Soc, vii.: 127, £ , 1878). 

 9 . — -Quite short and robust, the edge of the vertex passing before a line 

 drawn between the posterior margins of the eyes, one of the posterior 

 ocelli, therefore, nearer the vertex than to the neighbouring eye. 



This was identified for me by Mr. Cresson as M. optiva $ , and I 

 have indicated M. petulans as the male of that species, in Trans. Acad. 

 Sci., St. Louis, vii.: 350, 1S97. Lately, through the kindness of Dr. 

 Skinner, I have had an opportunity to examine the two type specimens 

 of M. optiva. They belong to two species, and neither of them is the 

 female of Af. petulans. One of them is, I think, the female of M.facunda. 

 The two species and M. sexdentata, Rob., may be separated as follows : 

 Middle metatarsus narrower than its tibia, apical ventral segment of 

 abdomen not reflexed, anterior margin of clypeus entire . . Af. optiva, pt. 

 Middle metatarsus as broad as its tibia, apical ventral segment of abdomen 



reflexed 1. 



1. — Apical margin of clypeus with a median and two lateral teeth, /. e., 

 5-toothed M. optiva, pt. 



Apical margin of clypeus smooth and shining, with a median dentiform 

 carina Af. sexdentata. 



In the preceding paper, Can. Ent., XXXIII., 229, sixth line from 

 the bottom, " anal rims " should read "anal rima " ; and on page 230, 

 "obliqua," repeated thrice in italics, should read " desponsa" 



