[Proc. Koy. Soc. Victoria, 23 (N.S.), Pt. I., 1910.] 



A in. 111. -^l Sj)/'ci('i< of A'lya.s, apparently nciv to 

 Science. 



By GEORGINA SWEET, D..Sc. (Melb.) 



(With Plate II.) 

 [Eoad lOth March, 1910.] 



Four specimens of " Fowl-tick " handed to me by Professor 

 Gilruth from a spirochaete-infected fowl apjjear at first sight to 

 be the hexapod larvae of J/v/c/.v iinnidfus, Koch, 1844, as hpured 

 by Salmon and Stiles (1901, jip. 405-7), which is now regarded by 

 Nuttall and others in their recent " Monograph of the Ixo- 

 doidea " (1908, p. 8) as synonymous with Argas persicus^ (Oken), 

 1818. But on closer examination they are found to differ in 

 several particulars from that form, especially in size, in which 

 they more closely resemble Argds re-'ijiertilioiiis (Latreille), 

 1796, and in the more ventral position of the capitulum, in 

 which they are unlike the larvae either of Aryas /iersicus or of 

 Aryas vexpertilioiils, though very similar to the nymph of A. 

 vespertilionis, figured and described by Nuttall (1908, fig. 50 

 and p. 37). 



The proportionate size does not appear to be related in this 

 case to the age of the larva, since the larva of Ar</(/s jursiciis. 

 wliicli is from .G to .7 mm. long, and al)Out the same in width, 

 simply liecomes longer as it matures ; whereas three of my 

 specimens are wider than long, the other circular, and all four 

 much larger than the hexapod hirva of Aryax //rrsiciis. it is 

 easily conceivaltle that Aryax rrspir/ iho/ns-. the bat-tick, should 

 be found on ii fowl, but not only arc these four specimens dis- 

 tinctly smaller than the larvae of A. re><pertiJioni.s, but they 

 differ in several (jther points from the lattei', as seen in the 

 following diagnosis. 



In view of the condensation of species of Argas by recent 

 workers, I hesitate to found a new species in the absence of 

 more material for comparison, but in order to avoid possible 



