312 
The Genus Ixodes 
was found on “ Viscaccia viscaccia (Mol.) ” at San Rafael, Province of 
Mendoza, Argentina, in 1910. 
The type is in Lahille’s collection, the types of the other stages 
(N. 2513-2515, 2517) are in Cambridge. 
Ixodes aurituius Neumann 1904. 
Figs. 14—16. 
The male of this species is still unknown. The female was described 
by Neumann and again by Nuttall and Warburton (Ticks, Part ii. 
pp. 187-189, Figs. 180-181), whose description is illustrated by Neumann’s 
original figures. These figures, except for that of the hypostome, are 
rather schematic. 
Having received some good specimens from Peru and British 
Columbia I take occasion to give an accurate figure and some notes on 
the female coupled with the first published description, with figures, 
of the immature stages. 
Female (Fig. 14): The new specimens (3 ?s) agree with the descrip¬ 
tion previously given in most particulars. The specimen herein figured 
was submitted to Neumann who agreed with our determination but 
thought that it might represent a variety owing to the scutum being 
slightly broader, the coxae slightly stouter and the legs somewhat 
longer than in the type. That the scutum varies in shape is clear to 
me, it may be either long or short as I have observed in other species 
of Ixodes. Two mutilated specimens from Tierra del Fuego, examined 
by us at the British Museum, and determined by Neumann, have long 
scutums with angular sides. The scutums of the three new specimens 
measure respectively 1*4 x 1*2 (? from Canada, N. 3178), T25 x 0-95 
and 1-0 x 0-8 mm. (?s from Peru, N. 2518, 2520). Variation is also 
shown in the dentition of the hypostome, that of the type is 616 followed 
by 4|4 rows of teeth; our Canadian specimen, here figured, shows 
dentition 5|5 followed by 4|4 and so does one of the specimens from Peru 
whilst the second Peruvian example shows dentition 313. We have 
observed similar variability in the dentition of the hypostome in 
Haemaphysalis leachi. In the new specimens the scutal punctations 
vary somewhat, the spiracles are short oval (rounded in the type), the 
porose areas of irregular form, the second and third palpal articles 
certainly fused. I consider that we are merely dealing with a 
species showing considerable individual variability in points of mere 
detail. 
