1889.] NATURAL SCIENCES OF PHILADELPHIA. 181 



Count Keyserling, however, in his extended and admirable mono- 

 graph 1 retains the species among the Retitelarise where it had 

 previously been placed. But the spinningwork of the spider, which 

 appears to have been unknown to the above named arachnologists, 

 shows conclusively that it must be placed with the Orbitelariae. To 

 that position, therefore, Dr. McCook assigned it, and it became 

 necessary to transfer the genus Theridiosoma from the Retitelaria? 

 to the Orbitelariae, and to make for it a new family, for which he 

 proposed the name Actince. 



In the paper above alluded to, in which the habits and spinning- 

 work of this spider were originally described, the statement was 

 made that the spiral lines of its web were covered with viscid beads. 

 Upon this point turned very largely the decision as to the true 

 systematic place of the spider, for it has never yet been observed 

 that any other spiders than those belonging to the Orbitelariae make 

 geometric webs that are habitually covered with viscid beads as the 

 ordinary armature for capturing prey. In correspondence with 

 arachnologists upon the subject* the speaker was not able to say 

 that he had made such tests of this point as to enable him to speak 

 with absolute assurance. He had made a somewhat careful investi- 

 gation with a good hand lens, wnich seemed to indicate with reason- 

 able certainty the presence of viscid spirals. But as the webs are 

 habitually located within cavities and shaded positions, where they 

 are extremely difficult to study, there remained the possibility that 

 he might have been mistaken. This appeared to be the more likely 

 because when such webs as those of the Triangle spider, Hyptioies 

 cavatus, are examined, the spiral lines often appear to be beaded, 

 although it is well known that they have no viscid armature. The 

 lack of beads is supplied by a thin floceulent thread, which is teased 

 or hackled by a special instrument known as the calamistrum. Yet, 

 when one looks at the spiral thread of Hyptiotes, or of U/oborns, 

 which has the same peculiarity, he finds that it presents to a care- 

 less glance the appearance of being beaded. More closely examined, 

 however, these seeming beads prove to be nothing but globular 

 grains of pollen or particles of dust which have been drifted upon 

 and entangled with the flocculent lines. The speaker had himself 

 more than once been deceived by the strong resemblance of these 

 drifted minutiae, and been led to look again with the wonder whether 

 after all there might not be beads upon these webs which were so 

 well known to be unbeaded ? When, therefore, the question was 

 raised and became of such special importance, he resolved to make 

 a careful and thorough re-examination and test of this point. 



No opportunity occurred to do this successfully until July 8th 

 (18891, near Wallingford, Delaware County, Pennsylvania. The Ray 

 spider was found in sufficient abundance for desired study, located 

 along the banks of a little run or stream of spring water. Its posi- 



1 Die Spinnen Amerikas. Theridiidae, I Hiilfte, von Graf. E. Keyserling, 

 Zweiter Band, p. 218. 



