340 ENTOMOLOGICAL NEWS. [Oct., 'l/ 



of them had evidently completed their allotted span of life as 

 they were dropping from the air in large numbers. 



One particular specimen flew past, almost brushing my face, 



and, as I thought, alighted upon the ground. As I stooped to 

 examine it the wings suddenly folded down tightly in front of 

 the body and I picked the insect up quite dead. 



Late in October, while collecting east of Eagle Pass, I came 

 upon a small pond upon the banks of which grew several quite 

 large mesquite trees. These trees were almost covered by 

 swarms of Monarchs (Anosia plexippus). They remained un- 

 til the following day, when nearly all of them left within an 

 hour or so. 



Two days later the willows growing upon the bank of the 

 Rio Grande were the resting place for a still larger swarm, 

 some of which remained several days. I enclose a picture 

 showing one of the trees. 



Descriptions of new Genera and Species of the Dip- 

 terous Family Ephydridae IV. 



By E. T. CRESSON, JR., Academy of Natural Sciences of 



Philadelphia. 



CEROPSILOPA n. gen. 



A fairly well marked genus closely allied to Psilopa but evi- 

 dently distinct ; apparently belonging to a group containing the 

 oriental Rhynchopsilopa Hendel. The sub-pendent nature of 

 the antennae, with the second and third joints apparently sus- 

 pended from the exserted first, is very characteristic, as is also 

 the hair-like apical spine of the second joint. Psilopa loiuji- 

 cornis Meijere and several undescribed species from the Orient 

 also belong here or to allied genera. 



Description. Head broad and high. Eyes bare. Frons 

 broad with ocellar tubercle situated at the sharp vertex ; ocellar 

 bristles situated between the post-ocelli ; the proclinate orbitals 

 and generally the reclinate frontals present. Face narrowed 

 at middle, convex to nearly carinate, not excavated at anten- 

 nae ; epistoma retreating. Antennae decumbent; second joint 

 without apical production, but with or without the hair-like 



