MORE AMERICAN SPIDERS OF THE GENUS 
CHRYSSO (ARANEAE, THERIDIIDAE)* 
By Herbert W. Levi 
Museum of Comparative Zoology, Harvard University 
In a previous paper (Levi, 1955) I revised the genus Chrysso , which 
I thought at the time to be a compact group of closely related species 
quite distinct from Theridion , and all coming from America. How- 
ever, soon after publishing a description of the genus Arctachaea for 
only two species (Levi, 1957), I discovered species intermediate 
between the new genus and Chrysso. 
Though species bridging genera have been found in various groups 
of theridiids, it was a surprise to see the description of Argyria venusta 
Yaginuma, 1957 (Figs. 3-5) from Japan, a species close to Chrysso 
and having similar habits, but less specialized in genitalic structure. 
Soon several other species were examined that are best placed in 
Chrysso unless we want numerous monotypic genera. One of these 
species is Argyrodes nigra O. P. -Cambridge (Figs. 1,2) from Ceylon 
(with genitalia superficially resembling those of Theridion punctospar- 
sum Emerton) though it has the palpus still less specialized than does 
Chrysso venusta (Yaginuma). Allied to Chrysso nigra (O. P. -Cam- 
bridge) is the American Chrysso nigrosternum Keyserling (Fig. 13). 
Several of the species now placed in Chrysso have the cymbium modi- 
fied [e.g. Chrysso perplexa (Keyserling), Fig. 18], and bridge the 
gap to the two species previously placed in Arctachaea. Further, a 
male of Chrysso cainbridgei (Petrunkevitch) (Figs. 43-47) bridges 
the gap between the latter groups and the species tentatively placed 
in Meotipa. Meotipa is a genus of doubtful validity; the male of the 
type species remains unknown. The three species placed in Meotipa 
differed from Chrysso mainly by their longer legs and by a somewhat 
different shape of abdomen. 
There is still some doubt that the groups considered in this paper 
are monophyletic. Certainly all are related to Theridion, from which 
they can be separated by the modified shape of the abdomen and by 
the more specialized palpus. The specialization of the palpus, how- 
ever, may go in different directions. Most species resemble the T . 
frondeum group. A distally truncate cymbium, otherwise rare in 
theridiids, is common in Chrysso and probably indicates relationship. 
Another unusual character, grooves on the sides of the abdomen, is 
found in some of the species here considered to belong to Chrysso and 
* Manuscript received by the editor April 18, 1962. 
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