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be a rather bold individual who would say that any distinctively 

 marked specimen which he found was a new species. Ixodidae 

 from Lizards had been described on many occasions ; they were 

 mentioned by Lucas, whose great work on the " Natural History 

 of Algeria " was remarkably complete, although his descriptions 

 of Ixodidae were not equal to his other subjects. The homologies 

 of the rostrum and mouth-organs were more or less understood, 

 but not so well perhaps as they might be if the comparisons 

 were less often made to the mouth-organs of insects instead of 

 to those of the Arachnida. Mr. Lewis was perfectly right in 

 saying that the larger number of writers upon the subject have 

 called that portion which carries the barbs the labium, and in 

 many other groups the same kind of use is made of the term. 

 But, for all that, the use of this term conveyed an entirely false 

 idea, because the organ was not the homologue of the labium of 

 an insect. It was really a maxillary lip formed by the fusion 

 of the maxillse ; they were completely fused together at the 

 base, and although they thus formed a kind of lip it was 

 certainly a maxillary lip. Its position and homology was 

 defined clearly by the palpi which were annexed to it, because 

 these were the maxillary palpi, and certainly not labial palpi. 

 In the same manner it had been asserted that the first paix of 

 legs really represented the labial palpi, thereby accounting for 

 the fact that whereas insects proper had only six legs these 

 creatures had eight. This supposition seemed rather taking at 

 first, but it was negatived by the fact that in the immature 

 stages there were only three pairs of legs, and that it was only 

 at a later stage that the fourth pair appeared, and when they 

 did so the}'- were found to be abdominal, and not belonging to the 

 Cephalothorax at all. The question as to there being two pairs 

 of mandibles had also been raised before by Haller and others. 

 He asserted that there were two pair of mandibles. Fusten- 

 berg also held that there were two paii's, but all the analogies 

 of the subject were strongly against it, although there might 

 be one pair of mandibles and one pair of something else beside. 

 The sheath was more or less common in many groups of Acarina, 

 but it did not assume the same form as in the IxodidjB. With 

 regard to the remarks made as to the inconvenience produced 

 by the attacks of Ixodes, so far from their being in any way 

 exao-gernted, he conld only say that they wore far below the 



