816 REPORT OF THE HARVARD AFRICAN EXPEDITION 
“The adult stage differs but little from the normal bird mite, except that there 
are two forms of the male — one which has considerable resemblance to the 
female and the other which has several secondary sexual characters, the an- 
terior pairs of legs being long and heavy and the immovable finger of the 
mandibles being greatly enlarged and lengthened. There is, however, an hypo- 
pial stage in the life of this mite which has been the theme of much discussion 
among acarologists for many years. This hypopial form was described by 
Filippi as Hypodectes and by Nitzsch as Hypoderas. Hypodectes is found in 
various parts of the internal anatomy of birds, generally in the areolar and 
peritracheal tissues. It is of an elongate form, rounded in front and behind, 
and with eight short legs, two pairs in front and two other pairs toward the 
posterior end. There are no mouth organs, and Slosarsky, who examined the 
anatomy, found no internal structures save a few muscles attached to the legs. 
From this it was evident that Hypodectes was a nymph in the state of hystoly- 
sis. Mégnin soon made a more extended study and found that the mite was 
a stage in the life history of a Pterolichus (now placed in the genus Falculvfer). 
Méegnin considers that when the Falculifer finds that it is being deprived of 
shelter and food by the birds pulling out their feathers, certain normal nymphs 
transform into the hypopial Hypodectes. This then crawls into the respiratory 
organs, or into the hair follicles, burrows some distance, and there remains 
until normal conditions are reestablished, when it reappears on the outside.’’ 
DERMANYSSIDAE 
Liponyssus bacoti (8. Hirst) 
Leiognathus bacoti S. Hirst, 1913, Bull. Ent. Res., IV, 2, p. 122( 9; Assiut, Egypt, off Mus norvegi- 
cus); 1914, loc. ctt., V, 3, p. 225, figs. 12-14 (# 9). 
Liponyssus bacoti Ewing, 1922, Proc. U. 8. Nat. Mus., LXII, Art. 13, p. 18, Pl. I, fig. 10 (4 9); 
1929, ‘Manual of External Parasites,’ p. 15, fig. 4. 
LipertA.— Paiata, sucking blood on the arm of man, October 15, 1926. 
Gbanga, off Rattus rattus alecandrinus (Geoffroy), September 22, 1926. (Deter- 
mined by Dr. H. Ewing). 
This is a common and cosmopolitan parasite of mice and rats, which has 
often been recorded as annoying man. It has been introduced into the United 
States. 
Liponyssus sp. 
Lrperta.— Ghbanga, off a squirrel, Heliosciurus rufobrachium maculatus 
(Temminck), September 16, 1926. 
This is possibly the mite described as Leiognathus liberiensis S. Hirst, 1912. 
Bull. Ent. Res., II, p. 371, fig. 2; ¢; off a squirrel at Rebbo, Bassa, Liberia. 
