. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology. CrcLOSA • Levi 303. Figures 1, 2. Araneid left palpi, diagrammatic. 1, Araneus. 2, Alpaida. Abbreviations. A, terminal apophysis; C, conductor; dH, distal hematodocha; E, embolus; M, median apophysis; PM, paramedian apophysis; R, radix; T, tegulum. evolved several times. Scharff and Cod- dington (1997) believe the "conductor lobe", which is apparently homologous to the paramedian apophysis, to have evolved three times. They reject homology of the paramedian apophysis and the conductor lobe because these char
. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology. CrcLOSA • Levi 303. Figures 1, 2. Araneid left palpi, diagrammatic. 1, Araneus. 2, Alpaida. Abbreviations. A, terminal apophysis; C, conductor; dH, distal hematodocha; E, embolus; M, median apophysis; PM, paramedian apophysis; R, radix; T, tegulum. evolved several times. Scharff and Cod- dington (1997) believe the "conductor lobe", which is apparently homologous to the paramedian apophysis, to have evolved three times. They reject homology of the paramedian apophysis and the conductor lobe because these characters appear in distal lineages in their cladogram (p. 419). But this is the logical result of considering them as separate characters to make the cladogram (p. 373). It is not surprising that an earlier draft of their manuscript had 60,000 possible parsimonious cladograms [as stated by Scharff and Coddington (1997: 403)]. The many homoplasies and later losses of characters used in their pre- sent cladogram are disconcerting. The publication states that the palpi were not very useful for the study of phylogeny. One wonders if the examination of several spe- cies of each genus would have prevented these errors. (Also see Other Characters below under the genus Cyclosa.) My own views are based on the study of genitalia, including the complex palpi, and the gross morphology of spiders, and are drawn from my generic revisions (Levi, 1995b). The phylogeny used is based on likely apomorphies. The genera of the Ar- aneidae can be naturally arranged into four or five groups: (1) Argiope and Gea, which have the posterior eye row procurv- ed and have reduced tapetum in the pos- terior lateral eyes. (2) Cyrtophora, Mano- gea, Mecynogea and Kapogea, which have the aggregate silk glands reduced or lack- ing and make horizontal dome-shaped webs without viscid silk. Both these groups have been accepted by Scharff and Cod- dington (1997), and follow Simon (1895). The third and fourth groups
Size: 2123px × 1177px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorharvarduniversity, bookcentury1900, booksubjectzoology
