124 
The Respiratory System of Mallophaya 
Of these Group A is undoubtedly of family rank, Trimenopon 
occupying a very isolated position. It shows a superficial resemblance 
to the Boopidae, but is without the accessory sac in the $ genitalia and 
the special sensory organs of the first three abdominal segments which 
characterise that family. In addition it exhibits a fusion of prothorax 
and mesothorax, a condition not seen elsewhere in the Mallophaga. 
Trimenojjon must rank as the type genus of a family Trimenoponidae. 
Philandesia, which I have not had an opportunity to examine, probably 
belongs here also. 
Group B has already been accorded family rank by Mjoberg (1910) 
on an examination of one species of Boopia. After examining a con¬ 
siderable number of species of Boopia and Heterodoxiis, and two of 
Latumcephalum, I agree that the Boopidae hold a very distinct position. 
Groups C and D, despite the difference in number of the stigmata, 
I leave for the present in the family Gyropidae, which was established 
by Kellogg (1896). But this difference further justifies Mjoberg (1910) 
in establishing a separate genus for G. gracilis', though this separation 
has not, apparently, been recognised by some later writers (Neumann, 
1912; Kellogg and Nakayama, 1914). I have not handled sufficient 
material of this family to venture any interference; but I think it will 
possibly be found that there is less uniformity among the species than 
is commonly supposed. 
Group E has already been accorded family rank by Mjoberg (1910) 
under the name of Physostomidae. As Neumann (1906) has pointed 
out that Pliysostoynmn, Nitzsch is a synonym of Ricinus, de Geer; and 
Johnston and myself (1911) that the family name Ricinidae must replace 
that of Liotheidae; it follows that this family, though now limited to 
two genera, must retain the name Ricinidae. 
Group F includes most of the remaining Amblycera. Mjoberg 
(1910) has established two families, Menoponidae, including a number 
of genera, and Laemobothriidae with a single genus. Of those genera 
not specifically mentioned by Mjoberg probably all may safely remain 
in the family Menoponidae with the exception of Ancistrona, which, 
on the structure of the lateral region of the head and antennary fossa, 
is quite as distinct as Laemohothrium, and is certainly entitled to family 
rank. There will thus be three families in the group, Menoponidae, 
Laemobothriidae, and Ancistronidae, towards the separation of which 
the respiratory system gives no help. 
Finally Group G includes the single genus Tetrophthalnms, and is 
only distinguished from the last by the transverse commissure of the 
