Marcus E 1951 (citation) pg. 117: 'Pistrix, n. gen., with the type P. thelura, n. sp. (Fig. 116-119), from fine sand between tide-marks of the canal of São Sebastião, belongs to the Monocelididae with vagina (Monocelidinae). The general aspect of the worms, their normal nuclei (en) in the most part of the body (depressed in the pre-cerebral region and in a small area around the genital pores, ea) and the tubular pharynx (f) suggested the approximation of P. thelura to Mesoda gabriellae. But as the male pore (p) is much farther from the orifice of the vagina (y) than from the female pore (q), the genus comes under no. 5 of the last key to the subfamily (Marcus 1950, p. 53). Minona and Monocelis have depressed nuclei; Meidiama has intra-epithelial ones on the whole body and different pharynx, male organ, and tail. Moreover it has a posterior bursa (resorbiens) that is absent in P. thelura.'
Notes from synonyms