G. H. F. Nuttall 
333 
Sub-order II. Siphunculata Meinert 1891. 
Characters of Sub-order: Anoplura with haustellate mouthparts, 
feeding only on blood which they suck after piercing the skin of the host. 
Piercing apparatus, when at rest, retracted within a diverticulum opening 
into the floor of the pharynx anteriorly. Thorax undivided (except in Ilaemato- 
myzus). Eyes present or absent. Antennae 3-, 4-, or 5-articled. Thoracic 
stigmata dorsal. Tarsi with one claw. Parasites of mammals. 
The Siphunculata are divided into four families: 
Salient differential characters 
1. Pediculidae Leach 1817. 
Type genus: Pediculus Linnaeus 1758 
With eyes, head not retracted 
into thorax, antennae 3-5-ar- 
ticled. 
2. Haematopinidae Enderlein 1904. 
Type genus: Haematopinus Leach 1817 
Eyes absent or very rudimentary, 
head retracted into thorax. 
3. Echinophthiriidae Enderlein 1904. 
Type genus: Echinophthirus Giebel 1871 
Antennae 4-5-articled, parasitic 
on marine animals only. 
4. Haematomyzidae Enderlein 1904. With pro thorax distinct, head 
Type genus: Haemcitomyzus Piaget 18G9 prolonged anteriorly as a long 
narrow tube, tarsi with a flat¬ 
tened hair-like structure ter¬ 
minating in a hook and arising 
alongside the claw, no tibial 
thumb 1 . 
N.B. This classification of the Siphunculata is the one usually accepted. The group was at 
first known by very few species, and it is only within relatively recent years that more have been 
defined. A multiplicity of genera have been founded, some obviously on characters of doubtful 
value, i.e. slight differences in external structure. The classification of the group as a whole will 
have to be recast when more species are known, their relations established, and their essential 
anatomical structures have been adequately studied. Such studies will require the use of other 
methods than the usual one of treating specimens with caustic potash and mounting them in 
balsam. 
We are only concerned herein with Pediculidae: 
FAMILY I. PEDICULIDAE Leach 1817, p. 64. 
Characters of Family: Siphunculata with head not prolonged anteriorly 
like a tube. Chitinous piercing organs, when retracted, barely attaining the 
thorax. Eyes large, protuberant, clearly pigmented. Antennae 3-5-articled. 
Tibia with thumb-like process and single incurved claw; no triangular pre- 
tarsal sclerite between tibia and tarsus (in contrast to Haematopinidae). 
Parasites of Primates. 
The Pediculidae contain two sub-families: (1) Pediculinae, and (2) Pedi- 
cininae: 
1 The mouthparts, on cursory examination, appear aberrant. They require to be studied 
so as to render the systematic position of the family secure. 
