18 Arachnida and Myriopoda 



of the parasites as about two millions, not including ova. Parasites 

 are well known to attack sickly animals in larger numbers than 

 usual, and this case seems to be merely an exaggerated instance of 

 this kind. 



A much more serious kind of itch, fortunately of rare occurrence, 

 has been found in Norway and several other parts of Europe. It 

 is characterised by the presence of white or yellowish crusts, which 

 make their appearance on the hands and arms or on the feet, 

 afterwards spreading to other parts of the body. Mites closely 

 resembling those of ordinary itch occur in large numbers in these 

 thick crusts. Norwegian itch, as it is called, is difficult to cure, 

 vigorous and prolonged treatment being necessary in eradicating 

 it. Furstenberg considered the mite that causes it to be a sub- 

 species or variety of the Itch-mite, and described it as Sarcoptes 

 scabiei crustosac. 



Varieties of Sarcoptes scabiei are found on various domestic 

 and wild animals, and those of the horse, goat, pig, dog, and others 

 sometimes transfer themselves to man when given the opportunity. 

 The itch-parasite of cats belongs to the genus Notoeclrus (N. cati, 

 Hering), the species of which have the anal opening placed well 

 on the upper surface of the body. Other species of the genus 

 Notoeclrus live in the skin of the rabbit (N. cuniculi, Gerl.), in the 

 rat {N. maris, Megnin), and in the mouse (N. musculi, Oudemans) ; 

 those of the cat and rabbit are communicable to man, causing a 

 transient eruption. 



Genus — Gytoleichus, Megnin. 



Whilst performing a postmortem on the body of a negro in 



Uganda, Castellani found two speci- 

 mens of an Acarid parasite deeply 

 imbedded in the fat of the omentum. 

 They were dark yellowish in colour, 

 the body being oval and furnished 

 with six legs (his figure shows eight). 

 This parasite is said by Castel- 

 lani to bear a strong resemblance to 

 Gytoleichus sarcoptoides, Megn. 

 F IG- 7, (= Cytodites nudus, Vizioli), an internal 



Gytoleichus hominis : an Parasite of the domestic fowl, and the 

 acarid parasite found by drawing which he gives in his note 

 Tf^X 'uganl 7 Mainly looks very like that speeies. 

 (After Castellani.) The palpi were very short ; the 



