TWO SPECJES OF PAPAS1TIC MITES. 337 



cure. Sulphur ointment applied repeatedly to the diseased parts is 

 said to effectually destroy the pest. A solution of Balsam of Peru 

 in alcohol, applied carefully, has also been highly recommended. 



PSOREKGATES SIMPLEX, N. G. & SP. 



While engaged in the study of Sarcoptes minor, a mouse was 

 brought to me which had a crusty scab on the lower part of the 

 back of the ear, extending round its outer edge and into the interior 

 of the conch, where it assumed the appearance of a tough, leathery 

 skin of a dirty grey colour. When a piece of this scab was pulled 

 off with the forceps and placed under the microscope, a number of 

 small mites were seen crawling over and burrowing their way into 

 it. At first sight they appeared to me very much like small, short 

 specimens of Myobia musculi, but a more careful study showed them 

 to be separated by many marked characteristics from this latter 

 species. It was seen, too, that they were all males, and that a fur- 

 ther search must be made for the females and young. I therefore 

 placed the scab in glycerine and tore it to pieces with needles, and 

 in this way brought to view a number of round, white specks, which 

 proved to be the females, nymphs and larvae, resembling the male in 

 very little else but the structure of the rostrum and the even distri- 

 bution of the feet along the sides of the body. 



This is in all probability the species mentioned by Gerlach, in a 

 book entitled " Kriltze and RSude," published in 1857, as occurring 

 on the ear of the common mouse, though on this point I am unable to 

 speak positively, as I have had no opportunity of seeing the original 

 description and figures. As M. Meguin, however, in his invaluable 

 work on " Les Parasites et les Maladies Parasitaires," says that it is 

 impossible to determine from the original figure even to what family 

 this mite belongs ; and as neither Megnin, in the book just cited, 

 nor Gerstilcker, in his review of Gerlach's work in " Archivs fur 

 Naturg eschichte," make any mention of a name having been given 

 to it, and as Fiirstenberg in his extended synopsis of Krdtze and 

 Rdude does not even notice the fact that an itch-mite had been 

 recorded from the mouse, it seems advisable to publish a new 

 description of it and give it a name. If it appears afterwards that 

 it has already received a name, the one now used will of course be 

 abandoned and the previous one adopted in its stead. 



