A HISTORY OF HERTFORDSHIRE ated in three groups a group of two in the centre and a group of three on each side. The only British species we possess is a well-known frequenter of houses in the southern counties, spinning an irregular web, and moving swiftly with a circular shaking motion when alarmed. 1 94. Pholcus phalangioides (Fuesslin). Hoddesdon (F. M. C.). Common but not abundant. MIMETID^E Spiders of this family are similar in general respects to the Tkeridiid&, having eight eyes and three tarsal claws. The species of Era construct a small brown pear-shaped or cylindrical egg-cocoon suspended on a fine silken stalk. 195. Era furcata (Villers). Hoddesdon (F. M. C.). This spider is known also as E. thoracica and Theridton vartegatum, Blackwall. DICTYNID^E The spiders belonging to this family possess three tarsal claws, and the eyes, eight in number, situated in two transverse rows, the laterals being in contact. The cribellum (or extra pair of spinning organs) and the calamistrum (a row of curving bristles on the protarsi of the fourth pair of legs) are present in all members of the family. They construct a tubular retreat with an outer sheet of webbing, which is covered with a flocculent silk made with the calamistrum from threads furnished by the cribellum. 196. Amaurobius fenestralis (Stroem). Hoddesdon (F. M. C.). Not so common as similis. Known also as Ciniflo atrox, Blackwall. 197. Amaurobius similis (Blackwall). Hoddesdon (F. M. C.). Common. Known also under the name Ciniflo. 198. Amaurobius ferox (Walckenaer). Hoddesdon (F. M. C.). Common. Known also under the name Ciniflo. 199. Dictyna arundinacea (Linnxus). Hoddesdon (F. M. C.). Abundant. Known also as Ergatis ienigna, Blackwall. 200. Dictyna undnata, Thorell. Hoddesdon (F. M. C.). 201. Dictyna latens (Fabricius). Hoddesdon (F. M. C.). Not common. Known also under the name Ergatis. 202. Lethia humilis (Blackwall). Hoddesdon (F. M. C.). Not common. Known also under the name Ciniflo. 203. Altella spinigera, O. P.-Cambridge. Hoddesdon (F. M. C.). A single specimen only ; probably an in- troduction from abroad amongst plants. Known also under Amphissa. hot-house the name CHERNETES CHELIFERID^E Out of the twenty species of false scorpions hitherto recorded as indigenous to Great Britain only two have been taken in this county. 204. Chthonius tetrachelatus (Preyss). Hoddesdon (F. M. C.). 205. Chernes nodosus (Schrank). OPILIONES The harvestmen are spider-like creatures with eight long legs, the tarsi very long and flexible. Eyes simple, two in number, situated on each side of an eye-eminence. Body not divided into two distinct regions by a narrow pedicle as in spiders ; abdomen segmentate. 206. Oligolophus ephippiatus (C. L. Koch). Hoddesdon (F. M. C.). 180
