Xn LIST OF ILLUSTRATIONS 



Facing page 

 mactlentus (Cresson); h, Polycyrtus neglectus Cushman; i, Acerastes 

 pertinax (Cresson); j, Mesostenus Ihoracicus (Cresson); k, Polyaenus 

 spinarhis (Brulk') ; I, Mallochia agenioides Viereck; m, Polistiphaga 

 zonata Cushman 4 



4. Hind trochanter and femur of: a, Derocentrus macilentus (Cresson); 



b, Mesostenus thoracicus Cresson 5 



6. Fore wix^g oi Acerastes pertinax (Cresson) 5 



6. The arcolet of: a, Agonocryptus discoidaloides (Viereck); b, Messa- 



toporus discoidalis (Cresson); c, Messatoporus major Cushman; d, 

 Mallochia agenioides Viereck; e, Listrognalhus albomaculatus (Cres- 

 son); /, Diapetimorpha orba (Say); g, Diapetimorpha introita (Cres- 

 son); h, Crypturopsis texanus (Ashmead); i, Polyaenus spmanus 

 (Brull6); 3, Mesostenus thoracicus Cresson; A;, Polycyrt^is neglectus 

 Cushman; I, Derocentrus macilentus (Cresson); m, Polycyrtidea 

 limitis Cushman; n, Acerastes pertinax (Cresson); o, Polistiphaga 

 fulva (Cresson) 5 



7. Agonocryptus discoidaloides (Viereck) 7 



8. Messatoporus discoidalis (Cresson) 10 



Further studies of types of American muscoid flies in the 

 collection of the vienna natural history museum 



By J. M. Aldrich 



1. Head of Cuphocera macrocera Wiedemann, male 26 



2. Lepidodexia tetraptera Brauer and Bergenstamm: 1, left lateral view 



of genital segments of male; 2, rear view of forceps; 3, rear view of 

 penis; 4, tip of penis; 5, rear view of accessory plate 32 



A NEW species of TRICHOSTRONGYLID worm of THE GENUS 

 COOPERIA from the CARABAO IN THE PHILIPPINE IsLANDS, 

 WITH A REVIEW OF THE GENUS 



By Benjamin Schwartz 

 1. Coopena nodulosa. Top view of head 2 



MlARGYRITE SILVER ORE FROM THE RaNDSBURG DISTRICT, 



California 

 By Earl V. Shannon 



1. Crystal of miargyrite thick tabular on c (001) 4 



2. Crystal of miargyrite thick tabular on a (100) 6 



3. Crystal of miargyrite tabular on c (001) 8 



Mineralogy and geology of Cerro Mercado, Durango, 

 Mexico 



By William F. Foshag 



1. Map of Cerro Mercado 5 



2. Crystal habit of apatite H 



3. Crystal habit of augite.. 14 



