6 J. H. Emerton — Nev^ Encfland TJierididm. 



they are simple round lioles or are united into a single hole, ' Grooves 

 or notches often extend from the holes to the edge of the fold, divid- 

 ing it into three lobes, the outer of which usually overlap the middle 

 one and partly conceal the grooves and openings. Various modifica- 

 tions of the shape of these lobes give the peculiar forms of the epigy- 

 num in many species, see figures of Tmeticus^ PI. XV. In some spe 

 cies a long flexible process extends backward from the middle of the 

 epigynum along the under side of the abdomen, and in Bathyphantes 

 and Microneta the whole epigynum is lengthened out nearly as long 

 as the abdomen, and folded up in two folds, so that the tip is nearly 

 covered. PI. XXI, XXII, XXIII. 



The palpal organ is a smooth bulb on the end of the male palpus, 

 from which projects a fine tube that fits into the epigynum of the 

 female. Inside the bulb is a sac, from which a fine duct extends to 

 the end of the tube, through which the spermatozoa are discharged into 

 the epigynum. In this family the palpal organ is usually i)arlly con- 

 cealed in a hollow in the tarsus. The tube, even when short, is 

 almost always accompanied by two processes, one hard and the other 

 soft and flexible, and most of the complications of the palpal organs 

 are produced by modifications of these three parts. The tube itself 

 varies greatly in length, in some species being long enough to wind 

 two or tliree times around the palpal organ, and is then supported at 

 the end by some of the ai)pendages of the bulb. In Bathypliantes 

 the tube is short aiul thick, and surrounded by long and comi)licated 

 appendages. Besides the i)ali)al organ itself, the terminal joints of 

 the pnlpus are modified in various ways. The tarsus is hollowed out 

 on one side, and the edges of this hollow are of various shajies to 

 support the parts within. At the base of the tarsus is an appendage, 

 which I call the tarsal hook, jointed to the tarsus at one end, and 

 extending sidewise around the base of the palpal organ. This part 

 varies greatly in shape, and is one of the most useful in the identifica- 

 tion of the smaller species. In the ThevUlhioi the tarsal hook is 

 absent. The tibia of the male palpus is usually more or less modified 

 in sha])e, having often a spine or hook on the upper part, extending 

 over the tarsus. Sometimes the jiatella is also modified. 



The webs of the TherkUda} consist usually of a flat or curved 

 sheet under which the spider stands, and which is supported by 

 threads running in all directions to the neighboring objects. In 

 some sjtecies these threads form a large mass over the web, and serve 

 to stop insects flying between them and make them drop to the flat 

 web below, where they are caught, by the spider. The webs of 



