GAMASJJDS. 



175 



CASE given by him in his paper are in general very accurate and 

 characteristic, especially considering the time when they were 

 made ; but this is not equal to the rest. There are various critical 

 points left unnoticed, and amongst others the number of joints tc? 

 the legs seems left uncertain. Professor Robin, however, before 

 whose knowledge of this subject we bow, regards it as a Der- 

 manyssus. If it be so, it must be one of the Garrasidae which 

 come under the genus Sejus, and ought to be removed from those 

 that are parasites on vertebrate animals. 



Sub-family Pteroptidae. 

 Genus Pteroptus {Dufotir). 



Readily distinguished by their very thick, short, and conical 

 legs, which are thicker and the joints shorter than in Dermanyssus. 

 The majority of the species composing it are either more or less 

 lozenge-shaped or baggy behind. AH the species are parasitic on 

 bats, to which they are confined, and they are sprinkled with 

 bristles, which are jomted in a manner not unlike the hairs of the 

 bats themselves. 



The resemblance between the structure of the hairs of the bats 

 and those of their parasites is certainly very remarkable. We give 

 a comparative view of a different kind of each in illustration of 

 this. 



m=i 



Magfnified hair of a species of Vampire, 

 after Queckett. 



Magnified hair of Diplostaspis dasycneintj 

 a European Fteropius. 



Here of course there can be no question of the resemblance 



