Four sclerotised spines on mesal side in shallow cavity; 1 apically, 1 at median of cavity, and 2 (one positioned below the other) at base of cavity.
Mesal plate long and fairly thin, extending beyond coxa and operculum, and hooking towards prefemur, covered apically in long hairs.
Mesal plate long and broad, protruding to 1/4 operculum height (Fig.
Chelicera: fixed finger with a shallow cup-like mesal ventral groove apically but otherwise normally rounded at the tip; no dorsal ridge, movable finger with a more flattened, triangular shaped anterior tooth; 2 intermediate teeth, posterior intermediate tooth separated from primary tooth; a small but discernable fondal notch (Fig.
Chelicera: fixed finger with small ridge basally on the dorsal edge, and a slightly hooked tip, ventral edge smooth with a short, deep mesal ventral groove apically (arrow, Fig.
Fixed finger regularly curved without teeth, shallow cup like mesal ventral groove apically, movable finger with normal primary tooth, flat pointed anterior tooth, 1-2 intermediate teeth separated from primary tooth.
Other definitions of the MA broadly agree that it is a distinct mesal process of the tegulum, typically, but not invariably, connected flexibly to the tegulum via a membrane (Lehtinen 1967; Shear 1967; Coddington 1986; Sierwald 1990; Griswold 1993).
Its topology is fairly consistent: the MA is usually positioned on the mesal side of the tegulum (often retrolaterally) towards the center or the base in the tegulum, further away from the embolus than is the conductor.
We agree with Levi (see Levi 1961 and Levi's numerous other publications on theridiids (1953-1972)) in considering MA in theridiids as a sclerite positioned retrolaterally on the mesal side of the tegulum (Figs.