So 



SCIENCE-GOSSIP. 



shows ralhei- an uncommon sUucture in legs of fresh- 

 water mites. There are two'very strong stiff bristles in 

 the joint, and the tarsi works in between these, at the 

 will of its owner (see fig. 2).^ Their function is, no 

 doubt, to give a greater grasping power to the little 

 . creature. In colour the legs and all the chitinous 

 parts of some specimens I have found to be of a pale 

 blue, in others a straw-yellow, same as the soft parts 

 of this mite. 



Epimera. — In four groups. The posterior pair have 

 a conspicuous looking gland near the inner line (see 

 fig. I.) 



Pai.pi . — Thin and rather long, being about o '28 mm. 

 in length, and are without the peg we met with in the 

 genus Liinnesia and some others. 



Genital Area. — Fig. 3, has three discs on each 

 edge of the genital plate. 



Male. — A little smaller than the female. The 

 arrangement of the genital plates is shown at fig. 4. 



Localities. — Not very common. My first specimen 

 was sent to me in 1895, by Mr. Scourfield from a bog 

 pool at foot of Cromley Fell in Yorkshire. In 1897 



1 found this species at East Finchley, Middlesex. 

 The same year I also took a great many in the stream 

 at Dovedale, Derbyshire. Dr. George has also found 

 it in Lincolnshire. 



GENUS DIPLODONTUS DUGES, 1834. 

 At present there is only one species placed in this 

 genus. Its characteristics are : Body soft-skinned. 

 Legs well supplied with swimming hairs ; Claws to 

 all feet. Eyes wide apart and near margin of body. 

 Palpi chelate. Genital plates covered with numerous 

 small discs. 



Diplodmiius despiciens MilUer, 1781. 

 Female. — Body : Nearly circular. Length about 



2 mm. Breadth about i "8 mm. Colour : Although 

 we only know of one species of this mite, we certainly 



Fig. 5. — DipkidonUcs despiciens. Ventral surface, female. 



have two varieties in Britain ; Variety I is a bright 

 red, with dark markings on the dorsal surface ; Variety 

 2 is a brownish yellow, with very dark markings on 

 the dorsal surface. These markings or patches are 

 traversed by veins of a creamy colour. The two 

 varieties are certainly very distinct, but I can find no 

 difference in structure. 



Legs. — First pair about o'S3 mm. Each pair^ 

 counting from the first, get longer as usual. All 

 the legs are rather weak and thin in appearance, but 

 to judge by the movements of the little creatures they 

 are not really so. The fourth pair of legs have more 

 swimming hairs than the others. In colour, the legs 

 are the same as the body tint, according to the variety 

 under examination. 



Fig. 6. Fig. 7. Fig. 



Diplodpntus despiciens. 



Fig. 6. — Genital plates, female. Fig. 7. — Palpus. 

 Fig. 8. — Nymph, ventral surface. 



Epimera. — These plates are rather small compared 

 with the size of body (fig. l). They are arranged in 

 four groups, two on each side of the median line. 

 Colour same as other parts of this mite. 



Palpi. — Thin, small, and chelate (fig. 3). 



Genital Plates. — As seen in fig. 2 are covered 

 with small discs, which appear to stand up in papular 

 form. 



Nymph. — (Fig. 4). The genital area of this stage 

 exhibits a great difference in having only 4 discs let 

 into the surface skin, which in the adult stage is- 

 succeeded by a great number on special plates. 



Localities. — The red variety is very common 

 everywhere. The yellow variety is not so common. 

 I have also noticed that the yellow variety, so far as 

 my own personal collecting has gone, has always 

 occurred in streams of running water and not in ponds. 

 I hope other students of freshwater mites will notice 

 if this is usually the case. 



(To be continued.) 



Shell Notes. — In May, 1897, I made several 

 excursions to Wicken F'en, Cambridgeshire, and found 

 specimens of Vertigo in abundance. Among the few 

 I kept, Mr. B. B. Woodward, F.L.S., F.G.S., has 

 kindly identified V. pygmaea^ and V. a}itivertigo. 

 The bulk of my specimens have been in the hands of 

 the official referee of the Conchological Society since 

 August, 1897, but, so far as I know, they are still 

 unidentified, officially. At Godmanchester, Hunts, 

 on July 6th current, in examining the Ouse back- 

 water, which runs through the causeway, I found a 

 young specimen of AuodoiUa anatina^ to which a 

 young Dreisseiisia polymorpha had become anchored. 

 The latter mollusc is fairly abundant in that back- 

 water. — ( Rev.) R. Ashington Biillen,F.L.S., F.G.S.,. 

 Little Stukeley Rectory, Hunts. 



