277 



TWO NEW SPECIES OF HYDRACARINA OR 



WATER-MITES 



Dartia Harris! gen. et sp. nov. and Eylais Wilsoni sp. nov. 



By Chas. D. Soar, F.L.S., F.R.M.S. 



{Read March 27th, 1917.) 



Plates 20, 21. 



While collecting Desmids on Dartmoor in August 1916, Mr. 

 G. T. Harris found several specimens of water- mites which he 

 submitted to me for identification. Amongst the specimens 

 were some from Broad Down Bog, near Postbridge, which proved 

 of more than common interest. These exhibited the following 

 noteworthy features : modification of second pair of legs, 

 absence of claws on fourth pair and swimming hairs entirely 

 wanting. There are several genera of Hydracarina in which 

 the claws above mentioned are absent, but they all possess the 

 swimming hairs. For the reception of this water-mite it is pro- 

 posed to create a new genus, and as the specimens were found 

 in the neighbourhood of the River Dart the name Dartia is 

 suggested. The only species of this genus at present known is 

 named after Mr. Harris — Dartia Harrisi. 



Dartia gen. nov. 



The body is oval in outline ; skin soft. The eyes wide apart 

 near margin of body. Legs without swimming hairs ; the fourth 

 pair of legs without claws. Epimera in four groups. Genital 

 area similar to that of Lebertia, but instead of the usual three 

 acetabula on each side of the genital cleft, there are four. The 

 palpi each have a long, stiff bristle on the flexor edge of the 

 second segment. 



