652 CONNECTICUT GEOL. AND NAT. HIST. g^JRVEY. [Bull. 



late; sides of mesoscutum with large punctures; mesoscuto- 

 scutellar suture strongly foveate; mesepisternum with large 

 punctures which are dorsally confluent melanognathus 



°R. caniculatus Say. 



*R. melanognathus Rohwer. • 



Manchester, 13 September, 1910 (A.B.C.). This is the type 

 locality of this species. 



SPHECID^. 

 By far the greater number of the Sphecoidea belong to the 

 family Sphecidae. As a family, the group is rather complex, 

 being composed of a number of types, but all of these are held 

 together by the presence of a prepectus. Within the family the 

 prepectus takes a number of forms, but in no case has any diffi- 

 culty arisen as to its presence or absence. 



Key to Subfamilies, 



1. Prepectal suture originating below lower margin of pro- 



thoracic tubercule, prepectus therefore wanting between 



tubercule and tegula Nyssonin^ p. 653 



Prepectal suture originating posterior to prothoracic tuber- 

 cule, prepectus therefore present between tubercule and 

 tegula 2 



2. Prepectus defined posteriorly by a strong carina which is 



angulate opposite prothoracic tubercule; an oblique suture 

 from below tegula to sternum, where it joins prepectal 



carina '. 3 



Prepectus defined posteriorly by a suture; no suture from 

 below tegula to prepectal suture 5 



3. Antennae inserted near middle of face; mesepisternum with 



a dorsal and ventral plate; abdomen petiolate; wings with 



three cubital cells Psenin^ p. 657 



Antennae inserted very close to dorsal margin of clypeus; 

 mesepisternum without a dorsal plate; abdomen sessile, 

 or subsessile; wings with one cubital cell 4 



4. First cubital and first discoidal cells confluent; propodeum 



with a process at dorsal middle; metanotum with processes 

 at sides; eyes with their inner margins subparallel 



OXYBELIN^ p. 659 



First cubital and first discoidal cells separate; propodeum and 

 metanotum without processes; eyes with their inner mar- 

 gins strongly converging below Crabronin^ p. 660 



5. Abdomen with a strong constriction between first and second 



ventral segments 6 



