SCIENCE-GOSSIP. 



to great advantage in collecting. One cannot go 

 to the Warren at any time of the summer season 

 without finding some votaries of some of the 

 natural sciences pursuing their hobby : geologists 

 with their hammers, entomologists with their 

 collecting nets, and the botanist with his tin 

 vasculum. 



At the bottom of several hollows in the Warren, 

 are some small ponds of water, and it was to these 

 ponds during August I paid several visits. Pond 

 life in the Warren has, I believe, received a good 

 deal of attention from some microscopists and 

 other naturalists ; but I cannot find that any 

 person has yet recorded the Hydrachnides found 

 there ; so it is to this interesting family of the 

 Acarina, I now wish to draw attention. 



In August, 1894, I was staying at Folkestone. 

 During that time I paid several visits to the 

 W^arren and collected all the Hydrachnides I could. 

 As I did not think I had found anj-thing like all 

 the species that occurred there, I contented myself 

 with making drawings and keeping a record of 

 what I did find, making up my mind at the first 

 opportunity to complete what I had then begun. 



This opportunity came in August this year. I 

 have done all I can to make the list as complete 

 as possible, but with all the time I have spent 

 there it is quite possible I may still have left 

 some species in the ponds undiscovered. If so, 

 some other naturalist, perhaps a member of the 

 Folkestone Natural History Societj- , or Micro- 

 scopical Society, will be able to add to those 

 species I now record. There is one male red 

 Arrenurus I should have liked to have taken. I 

 found the female, but I cannot, without the male, 

 give its name, so I shall have to leave this one out 

 of my list. 



There are in all about five small ponds of fresh 

 w-ater more or less covered with the common duck- 

 weed. These ponds are close together ; the largest 

 does not cover more than a hundred square yards 

 of surface, but small as they are, they teem with 

 life. I have visited these ponds a great many 

 times, and spent hours at each, so as to make the 

 collection of water-mites as exhaustive as possible. 

 I found representatives of ten distinct genera, of 

 which I give the list below. Where a figure has 

 already been given in England, and is easily 

 accessible to all lovers of natural history, it will 

 not be necessary to repeat that figure again, but 

 only refer to the reference. Of others I propose to 

 give an outline drawing to assist identification. 

 The ordinary collecting-net with glass tube at 

 bottom was used. The greater number of mites 

 were kept alive and examined on m}' return to 

 London. 



Genus I. — Eyiais (Latreille). Fourth pair of legs 

 without swimming-hairs. Eyes in centre of body. 



Eyiais exiendens (Miillerj. A large red mite, very 



common in the largest pond. It is easily recog 

 nized by its having two pairs of eyes close together ; 

 a small figure is given in " The Micrographic 

 Dictionary,"' 1SS3, plate 6, fig. 2S, which shows this 

 mite very well, but the hairs on the fourth pair of 

 legs are drawn too long. This species is not the 

 Hj'drachnid figured in Scienxe-Gossip under this 

 name in 1SS5. 



Gexcs II. — Limnochares (Latreille). .\11 legs 

 without swimming-hairs. E5'es in centre of body. 



Limnochares Jio'oseri-cea (Latreille). Red crawling 

 mite, very difficult to draw, on account of its con- 

 tinual change in shape ; common in same pond as 

 above. Ventral surface (fig. i). 



Genus III. — Diplodontus (Duges). Palpus short 

 and nipper-shaped, four eyes, two ventral and two 

 dorsal ; soft-skinned, swimming-hairs. 



Diplodontus despiciins (Miiller). Very brilliant- 

 coloured mite ; varies much in size. Common at 

 the Warren in 1894, but not this year. For figure 

 and description, see " International Journal of 

 Microscopy," October, 1S96. 



Genus IV. — Arrenurus (Duges). Swimming- 

 hairs, body chitinous, depressed line on dorsal 

 surface, epimera in three groups. 



Arrenurus caudatus (De Geer). A beautiful tailed 

 mite, common in first pond from East Cliff. See 

 Dr. George's figure in Science-Gossip, 1882, p. 273, 

 under name A . buccinator. The female is figured in 

 Scien-ce-Gossip, 18S3, p. 36. 



Arrenurus viridis (Duges). Not common at the 

 Warren, I only took a single male specimen, see 

 Dr. George's figure in Science-Gossip, 1882, p. 

 273, fig. 210. 



Genus V. — Ncsaea (Koch). Swimming-hairs, 

 body soft, epimera in four groups, numerous 

 genital suckers on each side of genital fissure. 



Nesaea- pulchra (Koch). A dark yellow mite with 

 pale-blue legs. Rather common. Fig. 2, ventral 

 surface. 



Nesaea convexa (Koch). A large dark-yellow 

 mite with a red mark on dorsal surface, short 

 palpus. Fig. 3 is the genital area only, the struc- 

 ture of this species otherwise being very similar to 

 fig. 2. The legs are a blue colour, dark. 



Genus VI. — Fiona (Koch). Swimming-hairs, 

 body soft, epimera in four groups. Three genital 

 pores on each side of the genital figure. 



Fiona ovata (Koch). Dark-j'ellow with black 

 markings, blue legs. For figure see "International 

 Journal of Microscopy," July, 1896. It will be 

 noticed that species of this genus are very much 

 like species of genus Ncsaea. That is so, but for 

 two distinctive features : three pores on each side 

 of genital fissure, and a small peg on palpi near the 

 fifth joint. 



Genus VII. — Hydrachna (Miiller). ' Swimming- 

 hairs, body soft, epimera in four groups, mouth 

 organs projected as far forward as palpi. 



