8 
Psyche 
[Mar. 
rangement of these eight pairs is therefore metameric 
and seems to be derived from the primitive segmentation 
of the opisthosoma. 
The “foveae dorsales” of the larva consist of only one 
sensillnm hastiforme each. The integnmental folds bend 
aronnd their openings, whereas on the contrary the open- 
ings of the other sensilla hastiformia lose themselves 
among the folds of the integument. Aside from the fact 
Text-figure 2. Arrangement of the integumentary sense organs of the 
larva of Hyalomma, dromedarii Koch: Fd, fovese dorsales; -Sa, 
sensilla auriformia; Sh ; sensilla hastiformia; Ss, sensilla sagitti- 
formia. 
that the openings are more conspicnons, they do not dif- 
fer from the usual type of sensilla hastiformia. 
Ventrally the body bears four pairs of sensilla hasti- 
formia. One pair lies very close to the sensillum sagitti- 
forme of the third coxa. In Rh. appendiculatus it is en- 
closed by the capsule of the sensillum sagittiforme, so 
that it is difficult to see. Though closely adjacent to it 
in the other species, the sensillum hastiforme is never- 
theless clearly set off. 
The number and the arrangement of the sensilla hasti- 
formia of the larva of Boophilus calcar atus Birula (PI. 
3, fig. 7) are similar to those of the Rhipicephalus, ex- 
