Type species: Ptychosyrinx chilensis Berry, 1968; here designated.

Description: Shell medium-sized (SL up to 45 mm), broadly fusiform, with prominent shoulder and moderately long, straight or slightly recurved, siphonal canal inclined to left. Suture shallowly im-pressed. Protoconch unknown. Subsutural cord not pronounced or weak. Subsutural ramp distinctly concave, smoodi except for thickened growth lines and sometimes shallow grooves. Peripheral cord not pronounced. Shoulder with large, distinct arcuate axial folds, 12-13 on last whorl, smooth or crossed by up to four low spiral cords. Last whorl with three to four unequal rounded major cords on base, adapical one strongest. Siphonal canal with four to five cords, weaker and more closely spaced than those on shell base, diminishing towards canal tip. Aperture (without canal) about 0.30 of SL. Anal sinus broad, shallow, with tip on shoulder. Coloration uniformly beige. Radula comprising about 95 transverse rows of teeth. Marginal teeth flat, with thickened edges, broadly bifurcating. Central formation distinct, with moderately long cusp, lateral extensions with visible borders.
Etymology: The genus is named after Johannes Thiele (1860 1935), the eminent Germán malacologist, in recognition of his lasting contributions to the studies of molluscs, including the description of many genera and species of Conoidea.

Included species:
Thielesyrinx chilensis (Berry, 1968) n. comb.

Remarks: The genus is monotypic. Conchologically, Thielesyrinx chilensis is very similar to some representatives of Cryptogemma, especially C. praesignis (E.A. Smith, 1895), but T chilensis differs in having flat marginal teeth with equally thickened, narrow, anterior and posterior margins, whereas these are shoe-shaped in C. praesignis (Zaharias et al., 2020: fig. 7).

Distribution: Presently the species is known from Chile from 75 to 360 m.