406 



PROF, B. T. LOWNE OF THE 



each tarsus, besides a few others. Tlie penis is placed on the 

 ventral surface in the median line between the hinder part of the 

 coxae of the third legs ; the vulva between those of the second 

 legs. 



I found the creature on the surface of, or very slightly buried 

 in, a depression of the skin lining the inner side of the external ear 

 of the short-tailed field-vole {Arvicola agrestis). I believe it to be 

 unrecorded, and propose to call it " Goniomerus muscuUnus.^^ 



DESCRIPTION OF PLATE XXVI. 



Fig. 1. Myocoptes tenax, Dorsal aspect. X 175. Drawn from a 



specimen with long abdomen. 



2. „ „ „ Ventral aspect. X 175. Drawn from a 



specimen with short abdomen. 



3. „ „ „ From the side. X 175. Natural position, 



holding the hairs of the mouse. 



4. „ ,j 6 • Dorsal aspect. X 175. 



5. „ ,, Ventral aspect. X 175. 



6. ,, ,, nymph. Dorsal aspect. 



7. „ >' $ • 3rd leg, seen from the inner side. X 350. 



8. Symbiotes tripilis, 5 • Ventral aspect, x 130. 



9. Goniomerus mtisculinus, . Dorsal aspect. X 175. (There is 



another pair of long hairs on the hind raai'gin, below and 

 hidden by the pair shown.) 



On the Structure of the Eetina of the Blowfly (CaUiphora ery- 

 throcephala). By Benjamin Thompson Lowne, F.E.C.S., 

 E.L.S., Hunterian Professor of Comparative Anatomy in 

 the Koyal College of Surgeons. 



[Eead 21st February, 1889.] 



(Plate XXVII.) 



In 1884 I had the honour of reading a paper before this Society 

 on the compound vision and morphology of the eye in insects, 

 which was published in the second volume of the new series of 

 ' Transactions.' 



That paper received at the time much adverse criticism, and 

 Dr. Hickson published a memoir in the ' Quarterly Journal of 

 Microscopical Science,' in which he convinced himself that he had 

 completely refuted my observations. 



