576 CLASS ix. 



Sarcoptes LATR. Body not furrowed between the second and 

 third pairs of feet. Third pair of feet remote by a large interval 

 from the four anterior feet. 



Note. Here are to be referred genera Trichodactylus DUFOUR and 

 Glycyphagus HEKING. 



Comp. E. HERING, Die Krdzmilben der TJiiere (1835), Nov. Act. Acad. 

 Leop. Carol. Nat. Curios. Vol. xvm. 2, p. 573 624, Tab. 43 45. 



Sp. Sarcoptes scabiei, Acarus siro scabiei L., BONONNI Observationes circa 

 viventia &c. Homes, 1691, fig. 113 DE GEER Mem. vn. PL 5, figs. 12, 13 ; 

 DUGES Ann. des Sc. not. 2e SeYie, in. PL xi. B; GUERTN Iconoyr., Arackn. 

 PL 5, fig. 12 ; SCHMIDT'S Jahrbucher f. Med. 1852, Bd. 76. s. 204. This 

 species, which has been very incorrectly confounded with the cheese-mite, 

 digs into the human skin 1 , and causes the itch. Other species occur in 

 animals. Here belongs, for instance, Sarcoptes equi (commonly regarded as 

 the Acarus exulcerans L.) HERING 1. 1. Tab. 43, figs, i, 2, DUJARDIN 

 Observ. au microscope, PL 16. 



See on this subject the interesting Medeelingen van Dr D. H. VON 

 LEEUWEN in the Nederl. Lancet 1 846, and his treatise Over de Schurft der 

 Dieren in A. NUMAN'S Vee-artsenijlcundig Magazijn, vi. 1847, l>lz. 52 159, 

 met 2 pi. HESSLING in theMilnchener medicinishen Zeitung 1852, Bd. 76, 

 has described some new parasitic mites in plica polonica of the human 

 subject. 



Note. In this family is commonly enumerated an elongate ani- 

 malcule found within a few years by SIMON in the sebaceous follicles 

 of the skin of the face, which scarcely has its place here. In the 

 short, conical feet, it agrees with the Arctisca s. Colopoda. 



Compare G. SIMON, Ueber eine in den Icranken u. normalen Haar-sdcke 

 des Menschen lebende Milbe, MUELLER'S Archiv /. Anat. u. Physiol. 1842, 

 s. 218237, Ta k. xi. 



Demodcx folliculorum, OWEN'S Lectures on the comp. Anatomy of the invert. 

 Animals, pp. 251, 252, 2nd ed. p. 444, 445. The same, or a nearly allied 

 species, was found in the pustules of a mangy dog in numbers, by Mr TOP- 

 PING, OWEN, p. 445. 



Dermaleichus KOCH. 



Consult Uebersicht der Arachniden- Systems, Illtes Heft 3, 1843, pp. 



122 126. 



Family IV. Notaspidea. Body defended by a horny, hard 

 covering. Mandibles chelate. Palps fusiform, quinquearticulate. 



1 That this animalcule resides here, and not in the pustules, was already expressly 

 announced by NYANDER, LINN. Amoenitat. Acad. v. p. 95. 



