May 1S90.] 



PSYCHE. 



343 



two species differ, as is the rule in the 

 genus, much less than the males. The 

 female variabilis has pale cilia on the 

 tegulae and the fore tarsus blackened 

 from the tip of the first joint, whereas 

 the female germatius has black tegular 

 cilia and only the terminal joint of the 

 fore tarsus black. I have seen one fe- 

 male, the exception above alluded to, 

 that had half of the tegular cilia yellow, 

 and half of them black. 



I am quite certain that the female 

 germamis was known to Loe\v. He 

 says, after mentioning the fact that D. 



variabilis is more variable in the color- 

 ing of the posterior tarsi than is usually 

 the case with the species of the genus 

 Dolichopics : ''I possess also some other 

 females which I can only distinguish 

 from the above described 9 of D. va' 

 riabilis by their black ciliated tegulae' 

 It seems therefore that either the females 

 vary in the coloring of the cilia, or that 

 we have here two exceedingly similar 

 species." Loew with his usual care and 

 circumspection did not venture to de- 

 scribe these females as a new species. 

 ( To be continued.^ 



NOTES ON THE STRUCTURE AND HISTORY 



SERRATA. 



OF HAEMATOBIA 



BY JOHN B. SMITH, NEW BRUNSWICK, N. J. 



During the summer of 1SS9 the alarm 

 occasioned by the appearance in exces- 

 sive numbers of this species, known as 

 the "'Horn Fly," induced me to study 

 some of the structures rather carefully 

 to demonstrate the impossibility of in- 

 juries such as were charged to the fly. 

 The result of these studies appeared in 

 popular form in Bulletin 62 of the New 

 Jersey Experiment Station, and as they 

 cover some ground not heretofore trod- 

 den, I give some of them in a more 

 technical and condensed form to the en- 

 tomological public. 



The inouth parts were more particu- 

 larly studied — not so carefully as the 



studies made on some other species by 

 Dr. Dimmock, but simply to show the 

 gross anatomy. In this species the 

 opercular sheath is a ringed structiue, 

 enlarged basally and roughly shaped 

 like an "Indian Club." The tube is 

 not complete, but there is an infolding 

 above and in front of the sheath which, 

 while making it practically tight, gives 

 a wide range of motion in enlarging and 

 and contracting. On the outer side 

 this sheath is furnished with rather 

 sparse hair set into deep pits, evidently 

 tactile and specialized, and not mere 

 pubescence. In general structure Sto- 

 moxys calcitra)is which was studied 



