— 92 — 



lining at the up[)er part (tftlie tube. When the viscid fluid coming from 

 the spinerets cools before it is applied to an object it forms a broad band 

 or ribbon as it might be called; by elevating and depressing the body 

 perpendicularly as shown in fig. 14,* and touching the spinerets here and 

 there to the wall cif the tube this ribbon of silk is fastened. By moving 

 around the tube at the same time the lining is made complete for 

 the perpendicular distance covered by the spider in its movements. Some- 

 times instead of elevating and depressing in the manner just described the 

 spider will move around the tube fastening the ribbon in circles. 



Figs. 15 and 16 represent a novel way of excavating a hole which I 

 witnessed in the case of a mature spider. With its legs as supporters on 

 each side of the tube it would elevate its abdomen in the air and hook its 

 mandibles in the earth at the bottom of the hole; then revolving through 

 a quadrant about the axis at ^, fig. 15, it would bring the earth to the 

 surface and push it off with its palpi as shown in fig. 16. 



From this study we may conclude the young of trap-door spiders 

 build then" nesls instinctively; that males as well as females build lra[)- 

 door nests before the sexual character and habits are well developed, 

 which in the case of the males make a somewhat wandering habit neces- 

 sary in order to find the females; that young and old vary in making their 

 nests from the normal type, so that the position or relative sloping of the 

 door or tube could not be of any value in the classification; that this 

 species does not use its legs to aid in spinning the lining to its tube, and 

 that they spin the lining at the upper end of the tube first; and lastly that 

 they vary in the degree of skill manifested as artificers and the maturity 

 of instinctive power.* 



EXPLANATIOX OF PLATE. 



Fig. I. a. Young trap-door spider, natural size, b, section of nest w.th open 

 door, built in noimal way, also natural size. tigs. 2 and 3 curved tube M'ith slant- 

 ing door. Fig. 4, trench with wall each side seen from one end. l;g. 5, arch cuii. 

 necting walls. Fig. 6, same, closed at one end. Fig. 7, same, witii trapdoor built 

 at the other end. Fig. 8, another built on same plan, but the lir-t opening not cpiite 

 closed, a loose flap at a. Fig. 9, tube dug between two walls, liinge at U, distal part 

 of door at b. Fig. 10, curved tube with door hung so as to swing to the right and 

 left. Fig, II, section of bottle showing work of spider: a, wall, b, pellets of earth 

 carried up and stuck to the glass, c, nest, a tower against the side of the bottle. Fig. 

 12, nest showing concentric "lines of growth," in the trap-door. Fig. 13, b, first hole 

 dug by spider, c, second one, d, wall between which was removed making of the ex 

 cavation a trench, subsequently d. was restored and nest built in normal way at /*. 

 Fig. 14, spiders rcpre.sented in act of spinning silken lining to the upper end of th-; 

 tube. Figs. 15 and 16, adult spider taking a novel method of excavating a hole. 



Note. — The doors of all the young trap-door spiders' nests are very thin, from 

 2 to 3 mm. in thickness. One spider worked so rapidly that it would sometimes 

 pick up and unload a pellet of earth in 8 seconds. As a ride they recjuired a much 

 longer time than this. 



* All of the observations made use of in the preparation of this article were made 

 on individuals of the same species. Descriptions of the new species collected, their 

 nests, and food habits, I jiope to have published in a subsequent article. 



