228 
Psyche 
[December 
Records. Brazil. Guanabara: Paineiras, Cidade Rio de Janeiro, 
22 Jan. 1949 (A. M. Nadler, AMNH). Sdo Paulo: Jabaquara, 
Cidade Sao Paulo, 21 Dec. 1945 (H. Sick, AMNH); Sao Paulo, 
13 Jan. 1959 (A. M. Nadler, AMNH). 
Thwaitesia O. P. -Cambridge 
Thwaitesia O. P.-Cambridge, 1881, Proc. Zool. Soc. London, 1881: 766. 
Type species by monotypy: T. margaritifera O. P.-Cambridge, 1881 from 
Ceylon. 
Description. Carapace nearly circular. Posterior median eyes 
separated by their diameter or less. Chelicerae small, without teeth. 
Legs long, first patella and tibia 2.0-3. 5 times carapace length. Abdo- 
men usually higher than wide with silvery spots. The genitalia are 
similar to those of Spintharus. Both have palpi with a large con- 
ductor and duct looping through the median apophysis (Levi and 
Levi, 1962). 
Diagnosis. Separated from Argyrodes by having two setae in 
place of colulus, from Episinus by different shape of abdomen (Figs. 
14, 15), by lacking horns in eye region and not having tubercles. 
Thwaitesia differs from Spintharus by having the posterior median 
eyes closer together. 
Distribution. Probably world-wide in tropics. Four species from 
America. 
Proble?ns. Two of the four American species are known from the 
type specimens only. The two other species, T. affinis and T. brac- 
teata are widespread and probably have been confused with each 
other, a reason for not copying literature records. It is of interest 
that the species have not been collected in the same vicinity; they 
may have similar ecological requirements (Map 2). 
In the American Museum of Natural History is a Thwaitesia 
with an epigynum similar to that of T. bracteata but with ducts 
parallel and seminal receptacles more anterior. The abdomen is 
low, subtriangular, widest anterior and without silvery spots. The 
specimen is from Minnehaha Springs, 700 m, Pocahontas County, 
West Virginia, July 1948 (K. W. Haller) and is believed to be 
exotic. 
Figure 2. Variation in palpal structure of Spintharus south of the 
United States. K. Manzanillo, Colima, Mexico. L. Huauchinango, Puebla, 
Mexico. M. Las Casas, Chiapas, Mexico. N. Tenejapa, Chiapas, Mexico. 
O. Moca, Guatemala. P. San Isidro del General, Costa Rica. Q. El Volcan, 
Panama (one collection). R. El Volcan, Panama (second collection). S. 
Pico Turquino, Oriente, Cuba. T. Portland, Jamaica. U. Loma Rucilla, 
Dominican Republic. V. Rio de Janeiro, Brazil. W. Utcuyacu, Junin, Peru. 
(K-U, W are S. flavidus ; V is S. gracilis) 
