88 



1831. Theridium quadri-signatum Hahn , Die Arachn., I, p.80, Taf. XX, fig.59 . 



1832. Drassus phaleratus Sund., Sv. Spindl. Beskv., in Vet.-Akad. Handl. 



f. 1831, p. 133. 



1833. Asagena phalerata id., Consp. Arachn., p. 19. 



1839. „ serratipfs C. Koch, Die Arachn., VI, p. 98, Taf. CCIV, 



figg. 502, 503. 



1864. Theridium signatum Black w., Spid. of Gr. Brit., LI, p. 205, PI. 



XIV, fig. 135. 



1869. Asagena serratipes Menge, Preuss. Spinn., IH,p.256, PI. 49, tab. 152. 



Panzer's specific name has, as we here see, priority in prefe- 

 rence both to Walckenaer's and Schrank's. — It was in this spider 

 that Westring first discovered that remarkable organ near the peti- 

 olum in the males of many Theridioidse, viz. the organ of stridulation , 

 consisting of an elevated arc round the base of the abdomen , by the 

 friction of which against the transversely striated base of the cepha- 

 lothorax a clearly audible , creaking sound is produced '). He after- 

 wards 2 ) discovered the same organ in Steatoda Upunctata and S. 

 guttata , as also 3 ) in S. castanea , S. versuta ( Ther. hamatum Westr.) 

 and Lithypliantes corollatus (2'her. albomaculatum Westr.). The pre- 

 sence of this organ appears to me evidently to prove, that at least 

 these spiders, as well as the stridulating insects, possess the power 

 of hearing, although we cannot in them, as in some of the latter, 

 detect special auditory organs. Packard 4 ) communicates a curious 

 notice, apparently connected with this subject, of a North American 

 spider: "We have," says he, "a species of spider, which makes a 

 noise somewhat resembling the purring of a cat: during the pro- 

 duction of the sound the body makes a tremulous motion it is said." 



(Pag. 175.) 15. Th. undulatum [= Theridium inuhilatum Westr. 



1861]. 



Of this species I have only seen a $ (jun.?), determined by We- 

 string, which was obligingly lent to me by Prof. Stal. In general 

 appearance it approaches nearest to the genus Lithyphantes nob.: in 



1) Om stridulations-organet hos Asagena serratipes, in KrOyer's Naturhist. 

 Tidskrift, Bd IV (1842—1843), p. 349 et seq. 



2) Bidrag till historien om Insekternas stridulations-organer, ibid., 2 Ba?kke, 

 Bd II (1847), p. 343. 



3) Beskrifn. pa stridul.-org. hos slagtena Pachycoris etc., in Gotheborgs Ve- 

 tenskaps- o. Vitterhets-Samhalles Handlingar, Ny Tidsfoljd, Hft 4, p. 53. 



4) Second annual Report on the Nat. Hist, and Geol. of the State of Maine , p. 212. 



