Gr. H. F. Nuttall 
301 
Ixodes dentatus var. spinipalpis Hadwen and Nuttall 1915, n. var. 
Figs. 6-8. 
In 1911 Dr S. Hadwen sent me specimens named as above, accom¬ 
panied by a short description and sketchy figures. Owing to difficulties 
in deciding about the determination the description of the variety has 
not hitherto been published. 
The specimens appeared to be more or less closely related to Ixodes 
fuscipes Koch 1844, 7. dentatus Marx 1899 and 7. boliviensis Neumann 
1904. 
The ? differs as follows from a specimen from Panama, determined 
as 7. fuscipes by Neumann (see Ticks, Part n. p. 169, Fig. 164), with 
which Mr Stanley Hirst of the British Museum kindly compared it in 
1911. In I. fuscipes the scutum is broader and more angular, the cervical 
grooves are almost obsolete, coxa I bears a much longer internal spur 
and a less distinct external spur; the auriculae are broader and blunter 
(palps and hypostome absent in the type at the Museum). These 
differences are also shown in a second specimen drawn by me {Ticks, 
Part ii. Fig. 163, from Neumann’s collection 1 ) in which the hypostome 
appears more pointed and the dentition 212; the spiracle distinctly 
larger, the tarsi more abruptly tapering, the pads as long as the claws. 
The descriptions we gave of the nymph and larva of fuscipes also 
differ from those of the new variety. We may therefore exclude 
fuscipes although the variety is closely related thereto. 
The $ was next sent to Washington where Mr Nathan Banks kindly 
compared it with the type of 7. dentatus, a mutilated specimen without 
palps, at the National Museum. From Banks’ report thereon, kindly 
communicated by Dr L. 0. Howard, our specimen differs from the 
type in having the scutum much longer and more evenly punctate; 
cornua a little more prominent; auriculae a little slenderer and perhaps 
pointing more downwards; coxa I with shorter and thicker internal 
spine; spiracle more elliptical. Mr Banks therefore considered it 
warranted for us to describe our specimen as a new variety or sub-species 
of 7. dentatus, adding that quite possibly the discovery of the d may 
ultimately show it to be a new species. Mr Banks adds that “ the figure 
of 7. dentatus rostrum in Neumann (reproduced by us in Ticks, Part n. 
Fig. 153) probably was not taken from the specimen now in Washington; 
in Marx MSS drawings there is a figure of the rostrum labeled dentatus ; 
1 Originally described as I. spinosus Neumann, the type was subsequently referred to 
I. fuscipes by Neumann aftei* he had examined Koch’s type. Specimen also from Brazil. 
