®9MOLOGICAL NEWS. 277 
; a close relation exists between the two forms. My 
eris of Ps. floridica has deteriorated considerably, especially 
+ larve and adults, so that comparisons in some particular 
MU cs ceca aon. 
ee  coerence & the size of the Missouri 
specimens, the larve of the latter being from one- 
Sie third larger. The difference in size also appears 
= ¢ pupa and adults. The Florida larve have eight or nine 
orsal plates on the posterior annuli of the abdominal segments, 
wh ¢ the Missouri larve have but six. The Florida larve 
ioe ee fe wane the Missouri ones have 
two: l widely separated plates on the posterior annulus of 
——— Each of these plates bears two long bristling 
_ In the living Missouri larve the internal organs show 
th the body wall as a broad creamy-white band in the 
| ‘of the fourth and fifth abdominal segments, which did 
SEE Giterences convince we These slight but uniformly 
astant differences convince me that this Missouri Psychodid 
ot the same as the Florida one, though certainly very closely 
ied. The adults have been compared with Ps. nocturnala 
_ and their similarity in every respect is so great that I feel sure 
they are the same species. The dates of their appearance also 
I find that my figures of Ps. foridica are slightly at fault 
‘on the segmentation of the posterior end of the abdomen. In 
some cases I find that the break between the last two annuli 
_ is so marked that I mistook it for a segmental rather than an 
_ annular division. 
- * LARVA. 
‘The larva is quite slender, cylindrical, measuring 11 mm. 
n length and 8 mm. in breadth. Each of the three thoracic 
_ segment: is rather distinctly divided into two annuli. The 
first abdominal segment also has two annuli, while each of the 
ee Each annulus of the 
abdominal segments has, on its dorsal surface, a 
© small chitinous shield; the third shield of each segment being 
