Mallophaga of Our Native Birds. 123 
These are called trabeculae. All these structures here named are specific 
characters in the determination of lice. * 
There is a uniform number of hairs present in the temporal and occipital 
margins. These hairs, as well as those of the prothorax, metathorax and 
abdomen are used as determining characters, as their number is uniform. 
Whenever these hairs seem to project through a clear space in the colored 
chitinized parts of the insect, they are said to be pustulated. 
Differences in genera involve more than the aforementioned facts. It 
depends mainly on the shape of the body, the size of the trabeculae, whether 
movable to any marked degree; upon the size of the front as compared with 
the occiput; the depth of the antennal fossa or ocular emargination, and 
the size of the temporal margins or regions of the occiput, generally indi- 
cated as swollen temporal regions. Another genus distinguishing character 
is the similarity or dissimilarity of antennae in both sexes. There are 
other differences in genera which will be noted in the accompanying key. 
It is the key as revised and standardized by Kellogg from his New Mallo- 
phaga I (1896) pages 61-62. 
Key to the Suborders. 
A. With filiform 3- or 5-segmented antennae, and no labial palpi. 
Suborder Ischnocera. 
AA. With clavate or capitate 4-segmented antennae, and 4-segmented 
labial palpi. Suborder Amblycera. 
Key to the Genera of the Suborder ]schnocera. 
A. With 3-segmented antennae: tarsi with 1 claw; infesting mammals 
(family Trichodectidae). Trichodectes N. 
AA. With 5-segmented antennae; tarsi with 2 claws; infesting birds (family 
Philopteridae). 
B. Antennae similar in both sexes. 
C. Front deeply angularly notched. Akidoproctus P. 
CC. Front convex, truncate, or rarely with a curving emargination, 
but never angularly notched. 
D. Species broad and short, with large movable trabeculae (at the 
anterior angle of antennary fossa). 
EK. Forehead with a broad transverse membranous flap pro- 
jecting beyond lateral margins of the head in the male, barely 
projecting in female. Giebelia Kellogg. 
EE. Without such membranous flap. Docophorus N. 
DD. Species elongate, narrow; with very small or no trabeculae. 
Nirmus N. 
BB. Antennae differing in the two sexes. 
C. Species wide, with body elongate-ovate to suborbicular. 
D. Temporal margins rounded; last segment of abdomen roundly 
emarginated; antennae of male without appendage, third seg- 
ment very long. Eurymetopus Tasch. 
