106 
The Resjnratory System of MallojyJiaga 
dorsal branch. A separate visceral element is not present. In the 
first and second segments the stigmatic branches are short, and end 
blindly, there being no corresponding stigmata. In the following 
six segments the typical arrangement is developed. The ventral 
branches arise in every case from the stigmatic branches, run towards 
the lateral margin of the abdomen, and turn ventrally, dividing into 
two main branches which are of much greater extent in the adult than 
in the young form figured. The dorsal branches arise from the main 
trunks in front of the corresponding stigmatic branches. These dorsal 
and ventral branches become greatly divided, and are distributed to 
all the body organs in an abundance of smaller branches, those of 
opposite sides freely mingling and crossing, but there is no anastomosis 
as far as visible branches are concerned, though a capillary anastomosis 
may be present. 
General Account—Introductory. 
For purposes of comparison I have examined species of the following 
genera: 
Amblycera. 
ISCHNOCERA. 
Ancistrona 
Akidoproctus 
Boopia 
Austrogoniodes 
Colpocephalum 
Degeeriella 
Eomenopon 
Docophoroides 
Eureum 
Giebelia 
Oliricola 
Goniocotes 
Oyropus 
Goniodes 
Heterodoxus 
Heteroproctus 
Laemohothrium 
Lipeurus 
Laiumcephalum 
Nesiotinus 
Machaerilaemus 
Ornithohius 
Menacanihus 
Oxylipeurus 
Menopon 
Pectinopygus 
Myrsidea 
Philopterus 
Nitzschia 
Physco7iella 
Pseudomenopon 
Pseudonirmus 
Ricinus 
Psittaconirmus 
Somaphantus 
Rallicola 
Tetrophthalmus 
Trabeculus 
Trimenopon 
Trichodectes 
Trinotori 
For opportunity to examine specimens of Nitzschia, Trimenopon, 
Euretim, Physconella, and Nesiotinus I am indebted to Messrs Gahan 
and Cummings of the Entomological Department, Natural History 
