CtASS IV, ACARr. 133 



Sp. 1, Uro. vegetans. Brown, very smooth, shining. 

 yihie vegetative. De Gecr., vii. I'ZS. pi. 7. fig. 15. 

 I ropoda vegetans. Lair., I^ach. 



Inhabits France and England, attaching itself to the legs, al.domen, 

 and elytra of Histcrex, Aphodii, &c. by its pedunculated anus. 



Fam. V. CiiEYLETiD.t. Leach. 

 Eyes distinct : palpi concealed. 

 Stiups 1. — Palpi distinct. 



Genus 9. SARCOPTES. Latrcillc, Leach. 



Sp. 1. Sar. Scabici. Subrotundate ; legs short, reddish ; four hinder 

 ones, \vith a very long seta : the plantai of the four anterior ones 

 tcnninated by a swelling. 



Mitte dc la Gale. De Gccr. Acarus Scabici. Fabr. Le Ciron de la 

 Gale. Geoff. Sarcopte de la Gale. Latr. Hist. Nat. dcs Crust, e.t dcs 

 Insect, viii. 53. et vii. pi. 66. Sarcoptcs Scabiei. Latr., Leach. 



Inhabits the ulcers of the itch. Acarus exulcerans of Linne is pro- 

 bably this animal, or is at least referable to the same genus. 



Section II. — Legs formed Jbr swimming. 



Fam. IIvLia.vciiNAUi. 

 Mouth with mandibles. 



Genus 10. IIYDIIACIINA. Mull., Olli:, Lair., Jxach. 

 Palpi subcylindric, porrcct, arcuate inlle.xed, four-jointed, the last acute 



uuguiform : mouth produced into a conic rostrum : bodt^ globose ; 



legs fimbriated with liairs, and situated at equal distances from eacli 



other. 

 Sp. 1. Ht/. geographica. Black, with coccineous spots and dots. 

 Ilydrachna geographica. Miill. Hi/dr. 59. tab. 8. Jig. 3-5. Lair., 



Leach. 

 Inhabits waters that flow gently. It is a most beautiful animal; and 



is very common near London. 



Genus 11. LOIXOCIIARES. Latr., Leach. 



Palpi incurved, the apex acute simple : mouth with a verj' short ro- 

 strum : body depressed : legs short, the four hinder ones remote : 

 eyes t^^'^o. 



Sp. 1. Lim. holosericea. Body ovate, red, rugose, soft; eyes black. 



Acarus aquaticus. Linn. La Tique rouge satinee aquatique. Geoff. 

 Mitte satinee aquatique. Dc Geer. Trombidium aquaticum. Fabr. 

 Limnochares holosericea. Latr., Leach. 



Inhabits Europe. It is very common in most of our ponds during the 

 summer months. It varies much in colour, but is generally found 

 of a bright red or greyish-red colour, and of all the int^rmedia,te 

 varieties of shape. 



