LINCOLNSHIRE FRESHWATER MITES. 



C. F. GEORGE, M.R.C.S., 



Kiiloti-hi-Lindsey, Lincolnshire. 



Piersigia limophila Protz. This is to my mind one of the 

 most beautiful and interesting- of all the water mites. It appears 

 to be scarce, and was first described by ' Protz' in ' Zoolog-ischen 

 Anzeig-er" for 1896, page 410. It belongs to Koch's division, 

 ' Sumpfmilben,' or mud mites, having no swimming bristles on 

 the legs ; it crawls about on the surface of the mud in a tolerably 

 active manner, but cannot swim. Its differences in structure 

 from all other water mites necessitated the formation of a new 

 genus, ' Piersigia,' and, so far, I am not aware that another 

 species of the genus has yet been discovered. I found it in 

 the parish of Manton, near Kirton-in-Lindsey, in April, 1902. 

 Its colour was a very rich scarlet, with dark blotches produced 

 by the contents of the caeca. The numerous plates of chitin 

 embedded in the skin are of various shapes, and complicated 

 structure, and are admirable objects for the microscope. The 

 thoracic plates are large, and clearly defined ; the g-enital plates 

 are large, and covered with acetabula ; the anal plate is of 

 singular shape, and thickly perforated ; and in addition to these 

 numerous plates there is a network of very fine chitinous threads, 

 reminding one of a suit of chain armour. The proboscis, or 

 snout, is circular at its apex, and can be either retracted or bent 

 underneath, and this the creature frequently does when crawling- 

 about. The palpi have the distal joint sunk somewhat into the 

 next internode, and the third joint has the distal end enlarged 

 and provided with a rather remarkable bunch of hairs. The 

 figures are sufficient to give a good idea of the creature, but 

 nothing short of actual examination under the microscope will 

 show clearly the complicated structure of the various pieces 

 of chitin. 



Piersig, in his description in 'Das Tierreich,' says 'sex 

 unknown.' My specimen, however, was unmistakably a mature 

 female, for its sack-like body was crowded with egg's, and 

 doubtless the specimens taken by Protz were also females. If 

 such be the fact, the male has yet to be discovered. 



Figure i represents the dorsal surface of the mite, and if 

 coloured scarlet (the legs a little paler than the body) would give 

 a good general idea of the creature, as seen under a low power 

 of the microscope. 



iqo3 April I. 



