Halbeut — Tlie Acarina of the Seashore. l-Sri 



ridges arc niucli less distinct. l'.ey;)ii(l the iiiiddlr tliere are two large pores 

 which are very conspicuous. 



Habitat. — Occurs between moist limestone Hakes on the rocky shore at 

 Malahide in tlie Orange Lichen and Pelvctia zones, and somewhat doubtfully 

 in the Spiralis zone. In these habitats tliey were in small colonies round the 

 outer edges of (he flakes, sometimes in company with the Tyroglyphid mite 

 Hyadesia fusca; also under stones resting on sandy mud at the mouth of a 

 small stream flowing into Malahide estuary. At Mulranny it occurred under 

 stones on the seashore. The dates of capture range from May to September. 

 Not previously recorded from the Britannic area. 



Scutovertex corrugatus Michael. 



Adults and nymphs common under stones on the Island saltniarsh in 

 Malahide estuary, May. At Mulranny it is very abundant under stones at 

 the mouth of a small stream flowing into Bellacragher Bay, September (25). 



Scutovertex maculatus Michael. 



Under tufts of a lichen (Lichina pygmaea) growing on exposed rock surfaces 

 at Malahide, in places washed by high tides ; with it were niimbers of a small 

 green Amphipod {Hyale Prevostii M. E.). Has also occurred on Lambay 

 Island (25). 



Scutovertex perforatus Berl. (PI. XXII, fig. 19.) 



1910 Berlese 13, p. 265. 191:} Berlese 15, p. 98. 



A few specimens were found under stones on a grassy sward amongst 

 Sea Purslane (Atriplex portulacoides) and othejf estuarine plants within reach 

 of high tides at Baldoyle, on the Dublin coast, November, 1917. This is by far 

 the smallest known species of Scutovertex ; the Irish specimens, measuring 

 o53/i X 176([<, are even a shade smaller than the Italian (o90yu x 210^). Notable 

 features' are the long setiform pseudostigiiiatic organs and the clear circular 

 spot near the front margin of the dorsum. In the brief description of the 

 species (13) Berlese says : " Derma dorsi aeque punctulatum." The dark 

 spots on the dorsum are really raised granules ; these are replaced on the 

 Cephalothora.x (fig. 19) by ridges. Not previously recorded from Britain. 



Hermannia scabra (L. Koch). 



Amongst calcareo\is tulla on a wall where fresh water flows through at 

 Malahide, probably washed by high tides. -Tune; also under flakes in the 

 Orange Lichen zone, dry to moist, August. At Ardfry it occurred under 

 stones resting on sandy mud and gravel in the Orange Lichen and I'elvctia 



