122 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



ains. 1 To the same group belong Emerton's Epeira sylvatica, and my E. 



bicentennaria. The species are closely related to each other and to the 



European Epeira angulata and E. bicornis. Systematists may 



Q hereafter unite them all into two or three species. The habits of 



the entire group, as judged by the species which I have studied, 



are like those of Insularis and Trifolium as above described. They dwell 



in silken tents or nests of rolled leaves, and spin webs of the type shown 



at Figs. 101 and 107. 



Epeira stellata is remarkable for the formation of its abdomen. Around 

 the sides are inserted a number of spines, one of which projects promi- 

 nently over the cephalothorax, which gives the creature a striking and 

 weird appearance. I have taken it, especially the young, in Pennsylvania. 

 New Jersey, and Connecticut. In the last named State numbers of the 

 species were seen occupying orbicular snares, which were spun low upon 

 grass, ferns, and golden rods oil the margin of a meadow near a stone 

 fence. They were of the general type of that group of 

 which Epeira strix is a representative. The spiders hung 

 at the centre with legs bunched up against the body, the 

 half grown individuals looking like seeds of certain plants. 

 The dull grays and grayish browns of its color helped to 

 make it inconspicuous against the background of the browii- 

 FIG. 109. Figure of ing foliage on which their snares were spun. At the least 

 Gasteracantha,fe- Disturbance the spider dropped suddenly to the ground, or 



ran for refuge to the foliage at one end of the web. 2 

 Among the Orbweavers constructing full vertical orbs is Gasteracantha, 

 a spider whose remarkable shape has attracted the attention of many ob- 

 servers. Fig. 109. I have received numerous specimens of Gaster- 

 as acantha cancer, and perhaps several varieties of the same, from 

 Mrs. Rosa Smith Eigenmann, which were collected in the neigh- 

 borhood of San Diego, California. On the Mesa land near the Mussel 

 Beds, and also along the bay shore in that vicinity, a great number of 

 specimens were found. The orbs of the spider were usually spread at a 

 considerable angle, occasionally nearly horizontal, and sometimes almost 



1 It was first made known by me in the Acad. Nat. Sci. Phila., under the name Epeira 

 harrisonae, after the lady from whom Mrs. Mary Treat (who sent me specimens) received it. 

 Emerton subsequently gave a detailed description and obtained priority. 



2 The measurements of one snare of an individual about half grown are given as fol- 

 lows: Orb, 6J x 6J inches in dimensions. Central space, 1J x 1J. Notched zone and hub, 

 f inch in diameter, of which the hub itself was T \ inch. The notched zone contained 8 

 spirals. The hub was slightly meshed. From the notched zone to the spiral space the dis- 

 tance was inch. The interspaces between the last 3 spirals of the notched zone were 

 much larger than those of the rest of the series, being ,' inch. The spinil sp:ice itself cov- 

 ered from 3 to 3J inches. The radii numbered 35. The spirals were 2(> below, 20 above, 

 and 21 at the sides of the hub. Another web was 5 inches in diameter, and was nearly 

 round in shape ; had 18 radii and 18 to 19 spirals. 



