No. 2312. 2^EW NORTH AMERICAN HYMENOPTERA—ROEWER. 225 



TABLE TO THE SPECIES. 



1. Propodeum uniformly sculptured; first and second tergites sculptured like the fol- 



lowing lophyri Viereck . 



Propodeum more coarsely sculptured medianly; first and second tergites more 

 coarsely sculptured than the following 2 . 



2. Third antennal-joint distinctly shorter than the fourth and fifth; carinae of the first 



tergite short, extending but a short distance beyond the middle; shining gastro- 



celi of the second tergite indistinct; four anterior femora partly black 3. 



Third antennal Joint subequal with the fourth and fifth; the carinae of the first ter- 

 gite extending much beyond the middle; shining gastroceli of the second tergite 

 distinct 4. 



3. Vertex and scutum closely punctured; face mostly yellow; sculpture on the first 



two tergites verj^ coarse; stigma more than three times as long as broad. 



canadensis Provancher. 

 Vertex and scutum with distinct well separated punctures; face mostly black- 

 sculpture of the first two tergites not nearly as coarse; stigma a little more than 

 twice as long as broad nigrijrons Rohwer. 



4. Four anterior femora pale; second tergite with very coarse punctures which are 



mostly confluent diprioni Rohwer. 



Four anterior femora mostly black; second tergite not as coarsely sculptured and 

 more of the punctures distinct affinis Rohwer. 



EXENTERUS LOPHYRI Viereck. 



In describing this species Viereck gave as host Lopliyrus townsendi 

 but it should be corrected to Neodiprion (Zadiprion) grandis 

 (Rohwer) . 



EXENTERUS CANADENSIS Provancher. 



Allotype female in the second Pro vancher collection, public museum, 

 Quebec, bearing a yellov/ label with No. 953 ; in good condition. 



Type. — Male is not in the public museum, Quebec, and has not 

 been examined. 



EXENTERUS AFFINIS, new species. 



Female. — Length, 8 mm. This species is very like diprioni and 

 except for the characters mentioned in the foregoing table the descrip- 

 tion of diprioni applies equally well to this species. 



Type locality. — Maine. Described from a single female recorded 

 under Bureau of Entomology No. Hopk. U.S. 12070/, and reared 

 from a cocoon of a species of Neodiprion sent in by a correspondent as 

 feeding on Pinus resinosa. The specimen issued May 18, 1915. 



Type.—Cat. No. 21060 U.S.N.M. 



EXENTERUS NIGRIFRONS, new species. 



This species is closely allied to canadensis but the characters given 

 in the foregoing table show the differences between the two species. 



Female. — Length, 8.5 mm. Face with close confluent punctures; 

 frons shining with distinct well defined punctures; strong semicir- 

 cular depressions around the ocelli; area between the ocelli and the 

 144382— 20— Proc.N.M.Tol.57 15 



