XII LIST OF IIX-TISTRATIONS. 



Page 

 2. A — venter, first abdominal segment of M. tibialis, showing ventral 

 margins of the tergite. B — venter, first abdominal segment of 

 M. communis. C — dorsum, first abdominal segment of M. com- 

 munis, showing the pair of fossae on petiole. D — venter, first 

 abdominal segment of M. indagator. E — venter, first abdominal 

 segment of M. dimidiatus. F — venter, first abdominal segment of M. 

 vulgaris. G — venter, first abdominal segment of M. hyphantriae. 

 H — dorsum, first abdominal segment of M. hyphantriae, showing 

 absence of fossae on petiole 6 



Crystallographic notes on Stephanite in a silver ore from Mexico 



By Earl V. Shannon 



1. Stephanite crystal 1 showing actual development 3 



2. Stephanite crystal 2 with forms (225), (290), (3-10-0) showing actual 



development 4 



3. Stephanite crystal 3 with forms (118), (3-10-5) and (3-11-3) showing 



actual develpoment 5 



4. Polybasite crj'stal showing actual development .-_ 6 



Revision of the North American wasps of the subfamily 

 Platygasterinae 



By Robert M. Fouts 



1. Amblyaspis californicus Ashmead. Abdomen of female 4 



2. Fidiobia flavipes Ashmead. Antennae, a, of the female, b, of the 



male 7 



3. Fidiobia rugosifrons Crawford. Antennae of male. Scape not 



shown 8 



4. Plaiygaster aphidis Ashmead. Abdomen of male 31 



5. Platygaster americana (Ashmead). Abdomen of female 32 



6. Platygaster solidaginis (Ashmead). Head of female, front view 66 



7 Platygaster salicicola (Ashmead). Abdomen of female 77 



8. Platygaster atriplicis (Ashmead) . Abdomen of female 79 



9. Platygaster asynaptae (Ashmead). Antennae 80 



10. Platygaster asynaptae (Ashmead). Abdomen of female 81 



The North American species of parasitic two-winged flies belonging 

 to the genus Phorocera and allied genera 



By J. M. Aldrich and Ray T. Webber 



1. Phorocera slossonae Townsend, male genitalia, much enlarged 49 



On the Taxonomy, Biology, and Distribution op the biting lice of the 



family Gyropidae 



By H. E. Ewing 



1. Monogyropus longus. Leg II showing tarsus locked in the furrowed 



crotch of femoral tenaculum. Dotted lines show position of leg 

 when extended 5 



2. To left, palpus of Protogyropus normalis; to right, palpus of Heter- 



ogyropus heteronychus 8 



3. Protogyropus normalis. Dorsal view of female X 90 9 



