150 
Prof. Miall and Mr. N. Walker on the 
II. — Condensed Account op our Pkesent Knowledge 
OP THE Early Stages op Psychodida:^ with Critical 
Kemaeks on some op the Publications. 
(The numbers quoted in brackets refer to the preceding 
List of the Literature.) 
Our present knowledge of the larvse of Psychodse we 
pnncipally owe to Haliday. His results are incorporated 
in the chapter on Phlehotomidae, as he called the family, 
in Walker's Insecta Brit., Dipt, iii., pp. 253-263 (1856). 
On p. 258, Walker says I am indebted to Mr. Hali- 
day for all the following characters of the genera and 
species of this family.^' 
The different groups of the larvae are characterized as 
follows : — 
Larva pale, terrestrial, the last segment slender, 
much elongated . . Psychoda (Latr.), Hal. 
Larva blackish, last segment little elongated_, jagged 
at the end and ciliated with radiating hairs. 
Larva with two double rows of lanceolate 
(gill- like) plates down the back. 
Ulomyia, Hal. 
Larva with two bands of curved hairs down 
the back Pericoma, Hal. 
Further details on the larv^ of the first group, Psy- 
choda, are given on the following pages : — 
(P. 255.) The larva of P.jphalsenoides, and that of P. 
sexpundata * inhabit dry cowdung ; they are long, sub- 
fusiform, depressed, with a slender, straight, cylindrical 
tail, which is longer than the preceding segment. The 
pupa has two short appendages, thickened at the tips 
behind the head ; the abdomen is tapering.^^ 
(P. 256, under the heading of P. sexpundata, Curtis.) 
" Respiratory auricles of the pupa filiform, curved, com- 
municating with the main trachea by a dilated cylindrical 
portion of the latter. In the larva ready for transfor- 
mation they may be seen, through the skin, forming an 
interrupted ring round the first part of the prothorax, 
beginning close to the spiracle and bent down till they 
nearly meet below, the thickened part of the trachea 
being also visible. According to my observations the 
* The synonymy of the two above-mentioned species is, accord- 
ing to Haliday (p. 255) : — Psychoda phalcenoides, Linn. (syn. P. 
7iervom, Meig., Perris). P. sexpiinctata, Curtis (syn. P. phalcenoides, 
Meig.). 
