THE NEOTROPICAL ORB-WEAVER GENERA CHRYSOMETA AND HOMALOMETA (ARANEAE: TETRAGNATHIDAE) HERBERT W. LEVM Abstract. Chrysometa and Homalometa are neo-tropical members of the family Tetragnathidae. Tet-ragnathidae are separated from Araneidae by the configuration of the male palpal parts, the large tar-sal organ on the cymbium and the cone-shaped pal-pal tibia. The female epigynum is flat rather than three-dimensional, often with complicated internal ducts; or rarely, the epigynum is absent. The abdo-men's integument is often underlain by evenly sized white or silver spots. Relative to body size, males have longer chelicerae than females. Tetragnathid males when mating hold females some distance from themselves. In many species the femoral-patellar joint is extended in resting position. There are 127 known species of Chrysometa, 94 of them new; there are three species of Homalometa, two of which are new. Most Chrysometa species oc-cur at high altitudes in the Andes and in paramos (both poorly collected areas); only a few species are known from low elevation rain forests. INTRODUCTION The study of Chrysometa was triggered by numerous inquiries from ecologists and collectors needing help with determina-tions. Unlike many other orb-weaver gen-era, Chrysometa is not readily recognized by ecologists or even by knowledgeable araneologists. While some Chrysometa species are found in low altitude forests and others at intermediate elevations, many are found at and above timberline. The mountains of Central America have proved unexpectedly rich in Chrysometa species, especially at higher elevations. The paramos of the Andes may have three or four species living sympatrically. The high altitude species are puzzling, since no two populations are quite alike. Is each pop-' Museum of Comparative Zoology, Harvard Uni-versity, Cambridge, Massachusetts 02138. ulation a separate species or does each represent a geographic form within a variable species? The placement of the metines, which include Chrysometa and Homalometa, has been controversial. Orb-weaver gen-era related to Meta are found in all parts of the world; the diversity appears great-est in the Indopacific. In American liter-ature they have been placed in the subfamily Metinae of the family Aranei-dae. Brignoli (1983) separated the metids as a distinct family. Other authors, how-ever, have recognized a relationship be-tween the metines and the tetragnathids. Simon (1895, 1929) placed the group in the subfamily Tetragnathinae of his fam-ily Argiopidae. More recently, Locket, Millidge and Merrett (1974) placed Meta of Great Britain in the Tetragnathidae, along with Tetragnatha and Pachygna-tha. In the present treatment I have also placed the metines in the Tetragnathidae, though I still have some doubts about the distinctness of this family. In my past re-visions of nearctic non-cribellate orb-weavers, all the genera were placed in one family (Levi, 1974, 1980a, 1981). Once it was recognized that the orb-web is a primitive character of web spiders (Levi, 1980b; Coddington, 1986), it could no longer be used as a synapomorphy to com-bine the araneids and tetragnathids; con-sequently, the relationship of the two groups required further investigation. The distinctive specialized (autapomorphic) features needed to define the family Tet-ragnathidae are still not satisfactory. However, as revisors remove erroneously included genera from Araneidae, the family becomes easier to define. Bull. Mus. Comp. Zool, 151(3): 91-215, November, 1986 91
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