ACARUS OF THE GENUN MYOBIA. 



masses, hanging from the walls or roof of the place, or even from 

 each other, and that these masses have been found to consist of 

 several species, if found in the neighbourhood; so that, if the para- 

 sites can live on various bats, they would be likely to become pretty 

 widely distributed. For these reasons I have not thought it desir- 

 able to select a genus of bats for the foundation of the specific name, 

 and provided it be, as I imagine, unrecorded, I propose to call it 

 Myobia chiropteralis. 



Myobia chiropteralis. Sp. nov., PI. I. 



I do not think it necessary in this description to detail the 

 numerous points in which the species is similar to the well-known 

 M. musculi, and which are, in effect, generic characters ; but only 

 to point out the particulars in which the new species differ from that 

 previously known, so as to facilitate identification. 



There is far less variation between the sexes in this creature than 

 in the Myobia of the mouse, the form of the males and females 

 being nearly similar. 



The principal differences from M. musculi are that M. chiropteralis 

 is the longer and narrower in form, and that the hairs on its dorsal 

 surface are far more spatulate than those of the mouse-parasite, and 

 mostly terminate in very long points, so that they really cover up 

 the greater part of the notogaster. The great holding claw of the 

 first leg also differs, and there are other minor distinctions. 



Myobia chiropteralis. 



Female (Fig. 1). 

 Average length about ... 



„ greatest breadth about 



„ leugth of legs, 1st pair about... 



,, ,, ,| _1HI ,, ,, ... ... 



,, ,, j, orcl ,, ,, ... ... 



n >> >> ^0. >> >> 



„ ,, anal hairs „ ... ... '35 ,, 



The form is longer and comparatively narrower than in M. musculi, 

 less wide over the third pair of legs, less rounded at the posterior 

 margin ; and there is a narrower, slightly-trifid projection for the 

 anus, which is absent, or but slightly indicated, in M. musculi. 



The most striking characteristic of the species consists in the 

 hairs on the back, which, instead of being straight and spike-like, 

 as in the mouse-parasite, are broadly spatulate, and are drawn out to 



