L. Harrison 
89 
thougli quite unimportant differences in form. As a matter of con¬ 
venience, therefore, I suggest a division into siib-genera, Rallicola s. str. 
confined to Rallidae; Parricola found on Parridae; and Aftericola on 
Apteiygidae. These divisions may be diagnosed as follows: 
Genus Rallicola, Johnston and Harrison. 
Philopteridae of small to moderate size; of a general form varying 
between that of Philojjtenis and Degeeriella, more resembling the latter; 
without distinct clypeal siiture; with slight to well-marked sexual 
dimorphism of the antennae; with a definite indication of two distinct 
articles in the tarsus; with the transverse bands of the abdomen 
continuous, or divided only by a narrow median line. The best 
characters are, however, found in the genitalia, which have a character¬ 
istic form, with straight (rarely curved) divergent parameres, having 
two small lobes at their bases, and a solid median portion, details of 
which will appear below in the description of the species; and in the 
genital plate and ventral pleural margins of the eighth segment of the 
?, which have a very characteristic chaetotaxy. The inner margin of 
the pleuron at its anterior end is produced into a process directed 
backwards and inwards, which carries three, more rarely two, stout 
spinous hairs; while the pleuron behind is densely covered with hairs 
arranged in two or three longitudinal rows. The genital plate is 
strongly convex, sometimes with a median emargination, and is closely 
fringed with one or more rows of shorter hairs, the more anterior of 
which are frequently reduced to small spines. These structures are 
unusual in the Ischnocera, and bear at least a superficial resemblance 
to those found in some Amblycera. The straight divergent parameres 
of the d, embracing a single sac-like median structure, are also remi¬ 
niscent of the Amblyceran condition; and it would seem as if Rallicola 
were a somewhat primitive Ischnoceran genus. 
Rallicola s. str. is confined to the Ralhdae, and is found upon all 
genera from the large forms such as Fulica, Porphyrio, Aramus, and 
Ocydromus down to small species of Rallus and Porzana. It possesses 
the characters detailed above, and is usually of small size, of the general 
proportions of a slender Philopterus, with the d much smaller than the 
$. The space between the hind border of the signature and the mandibles 
is uncoloured. Type, R. attenuata, Burmeister. 
