Science Gossip . reviously con-sidered in having two bristles bent into hook-shape SCIENCE-GOSSIP. 261 as shown in fig. 2 A. On the fourth segment, count-ing from the epimera, is a large stiff bristle of abayonet form. This peculiar feature renders identi-fication easy. This spur is about mm. inlength. Epimera.—Arranged in two groups. Pale yellowin colour, same as other parts of body. Palpi.—Rather thick, about mm. in length,and without the pegs we find in some other genera,but they have a number of small hairs. Genital Area.—One broad platewhich reachesnearly across the ventral surf
Science Gossip . reviously con-sidered in having two bristles bent into hook-shape SCIENCE-GOSSIP. 261 as shown in fig. 2 A. On the fourth segment, count-ing from the epimera, is a large stiff bristle of abayonet form. This peculiar feature renders identi-fication easy. This spur is about mm. inlength. Epimera.—Arranged in two groups. Pale yellowin colour, same as other parts of body. Palpi.—Rather thick, about mm. in length,and without the pegs we find in some other genera,but they have a number of small hairs. Genital Area.—One broad platewhich reachesnearly across the ventral surface of the body. It hasa number of small discs (fig. 1), about sixteen on eachside. Female.— I have not yet seen a female of thisspecies. Localities.—Found by Mr. Taverner near Oban, Only one male specimen at present representsthis species in Britain. Acercus cassidiformis Haller, 1882. Male.—Body a long oval, being about , and mm. in breadth. Yellow in colour,with brown Fig. 3. Acercus cassidiformis. Fourth leg of male. Legs.—Very similar to Acerais ligulifer, exceptthat it is without the spur on fourth segment. On thetarsi are two strong bent spines (fig. 3), which arevery prominent, but are quite different in shape fromthose on fig. 2. Epimera.—In the male appears to be all in onegroup, the line down the centre being very fine. Theepimera also appears to be laid on another chitinousplate, which covers the greater part of the ventralsurface and has a very granular appearance. This isa peculiarity I have not noticed on any other water-mite. Palpi.—Very like the palpi of the precedingmite. Length about o. 24 mm. Genital Plates.—Are much closer to theposterior margin of the last pair of epimera than?those of Acercus ligulifer. These plates are also let into the chitinous por-tion I have just mentioned. They extend nearlyacross the body, and have numerous discs on eachplate. Female.—A little larger than male, being lon
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