ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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5. Arachnida. 
British Trapdoor Spider. — Hugh Main (Essex Naturalist , 1922, 
20, 23-5, 1 pi.). An account of Atypus affinis in Epping Forest. It 
lives on ’gravelly banks, covered with tufts of heather. It makes a 
silken tube, which in the case of the mature female may extend three 
or four inches above ground, and eight to nine under ground. The 
tube is enlarged in diameter and length as the spider grows older, and 
Enock considered that individual spiders might live ten years. A 
swollen portion near the lower end may contain eggs or young. Main 
never found the male in the tube, but cases of this are known. The 
burrowing is done at night. The booty is caught in the aerial portion 
of the tube. J. A. T. 
Corsican Trapdoor Spider. — W. Morton (Bull. Soc. Vaudoise Sci. 
Nat., 1921, 54, 113-5). Notes on Ctenyza (fodiens) sauvagesi. The 
lid is disguised with pieces of moss or lichen ; there is a well-made 
silken hinge ; the smooth silk-lined shaft is 18 to 20 cm. deep ; there are 
minute holes on the under-surface of the lid for inserting the claws. 
The spider is nocturnal in its hunting. If a twig be pushed into the 
shaft the spider grips it with its mandibles and may be pulled out. 
J. A. T. 
Rare Spider. — P. I. Mercanton (Bull, Soc. Vaudoise Sci. Nat., 
1921, 54, 111). Notes on a rare spider, Porhomma thorelli (Herman), 
found in the salt mines of Bex and apparently confined to gypsum 
deposits. Although cavernicolous, it has normal eyes. It does not 
make a web, but uses a thread in ascending and descending. It was 
wrongly re-named (Batyphantes charpentieri) by Lebert in 1877. It 
has been known in the mines since 1867. J. A. T. 
Tracheal Tubes in Sarcoptidse and Listrophoridse. — Stanley 
Hirst (Journ. Quekett Micr. Club, 1921, 14, 229-36, 3 figs.). The 
mites of these two families are usually considered as Astigmata, 
without stigmata and without trachese. Megnin figures a supposed 
stigma in Chorioptes ecaudatus, and Trouessart affirms his belief in the 
presence of stigmata in Analgesidaa and Sarcoptidm. The presence of 
tracheal tubes has not been recorded for these families. But Hirst finds 
them in Otodectes cynotis var. cati, in Chirodiscoides caviae, and in an 
undescribed Listrophorid mite. J. A. T. 
New Species of Arrhenurus. — Ruth Marshall (Trans. Amer. 
Micr. Soc., 1921, 40, 168-73, 3 pis.). Descriptions of new species of 
this genus of water-mites from Ontario, Woods Hole, Wisconsin, and 
China. ‘ ' J. A. T. 
Pycnogonids of Arcachon. — L. Cuenot (Arch. Zool. Exper., 1921, 
60, Notes et Revue, 21-32). In this region there are five species, 
Nymphon gracile , Ammothea longipes, Anoplodactylus petiolatus, Chilo- 
phoxus spinosus, and Pycnogonum littorale. There are seven at Luc and 
nine at Roscoff, but only two in the Baltic. 'There are many in the 
