LOEW AS A DIPTEROLOGIST 
111 
mentioned on a preceding page) was given on page 10 of the 
“ Dipterologische Beitriige,” Yol. I (1845), where the whole group 
Tipulae gallicolae is divided into Section I, Polyneura, containing 
the Psychodidae, and Section II, Oliyoneura, containing the Ceci- 
domyiidae , and including also Zygoneurci Meig. and Anarete Halid. 
(Sciara is omitted in this table, perhaps from inadvertence). In 
all these attempts an undue prominence is given to the venation. 
The discussion in the “ Dipterologische Beitriige,” Yol. IV 
(Cecidomyiidae, 1850, p. 17), contains the same assertions on the 
close relationship between Psychodidae and Cecidomyiae, except 
that here Loew allows himself to go a step farther, and to intro¬ 
duce his section Tip. gallic, polyneura (Psychodidae) as a separate 
family: Tip. noctuaeformia. He says: “ The complicated struc¬ 
ture of the mouth-parts which enables some species to become 
blood-suckers, and the observation that the larvae of some of them 
(compare Schrank, ‘ Beitriige,’ p. 1) are aquatic and breathe with 
branchiae, are decisive.” 
The persistency of Loew in uniting the Psychodidae with the 
Cecidomyiidae, as late as 1850, proves that he had not paid atten¬ 
tion to a passage in the first letter which Haliday had written to 
him in September, 1847, and which I discovered among the manu¬ 
script annexes to that letter (compare my Chapter VIII, Haliday 
and Loew). This passage, written in Latin, refers to Psychoda in 
Curtis’s “ British Entomology, Diptera,” plate 745 (1839), and to its 
letter-press, in which Haliday had introduced a subdivision of this 
genus, adopting the new genera Saccopteryx, Trichomyia , and Sy co¬ 
rax. Haliday informs Loew in this passage that Psychoda, in the 
narrower sense, as defined in Curtis, requires a further subdivision 
into two genera: (1) Psychoda proper, and (2) Pericoma ; he adds 
a short definition. This explains why, many years later, in Walker’s 
“ Insecta Britarmica. Diptera,” Yol. Ill, p. 256, where Pericoma ap¬ 
pears for the first time in print, it is referred to as “ Haliday MSS.” 
In the same passage of his letter Haliday says about the relationship 
of the Psychodidae : “ Nexum hujus familiae cum Gallicolis probare 
non queo, et si nomina clarissima Loewius, Westwoodius in illam 
partem abierint.” He conjectures that these authors had been mis¬ 
led by the error of Bouch6 (“ exrore gravissimo permoti ”), who 
